Lesson 2 - ADHD and Anxiety

1. Introduction

ADHD and anxiety commonly occur together, and the relationship between them can be clinically complex. Anxiety disorders are more prevalent in people with ADHD than in the general population, but anxiety symptoms may also arise as a consequence of living with ADHD. Repeated difficulties with organisation, missed deadlines, academic or occupational pressures, interpersonal misunderstandings and previous experiences of failure can all contribute to persistent worry and anticipatory anxiety.

For the prescriber, the key challenge is not simply recognising that anxiety is present. It is understanding what is driving it. Symptoms such as restlessness, poor concentration, sleep disturbance, irritability and feeling overwhelmed can occur in both ADHD and anxiety disorders. A patient who appears highly anxious may have a primary anxiety disorder alongside ADHD, anxiety secondary to poorly controlled ADHD, medication-related symptoms, or a combination of these factors. Treatment decisions depend on making this distinction carefully.

This becomes particularly important when considering ADHD medication. Clinicians may understandably worry that stimulant medication will worsen anxiety, and occasionally it can. However, the presence of anxiety does not automatically make stimulant treatment inappropriate. In some patients, effective treatment of ADHD actually reduces anxiety because everyday life becomes more manageable: tasks are completed, demands feel less overwhelming and the individual has greater confidence in their ability to cope. In others, anxiety remains independently impairing and requires treatment in its own right.

Throughout this lesson, we will approach ADHD and anxiety from the perspective of the prescribing clinician. We will consider how to distinguish overlapping symptoms, recognise clinically significant comorbidity, decide which condition requires treatment first, understand how ADHD medication can affect anxiety, and monitor patients safely when both conditions are present.

This lesson builds on the course's earlier teaching on ADHD assessment, differential diagnosis, medication initiation, titration and monitoring. It also introduces an important principle that applies throughout ADHD medicine: comorbidity should rarely be approached as a simple question of whether another diagnosis is present. The more useful clinical question is how the different difficulties interact, which symptoms are currently causing impairment, and how treatment can be sequenced to achieve the best overall outcome.

2. Learning Outcomes

By the end of this lesson, learners should be able to:

1. Understand the relationship between ADHD and anxiety, including the prevalence of comorbid anxiety disorders, the ways in which ADHD can contribute to anxiety symptoms, and the impact of anxiety on functioning and treatment outcomes.

2. Differentiate ADHD symptoms from anxiety symptoms, recognising areas of clinical overlap and identifying when anxiety represents a separate psychiatric disorder rather than a secondary consequence of ADHD.

3. Conduct a comprehensive clinical assessment of anxiety in patients with ADHD, including identifying specific anxiety disorders, assessing symptom severity, evaluating functional impairment, and recognising relevant risks and differential diagnoses.

4. Develop an appropriate treatment strategy for patients with coexisting ADHD and anxiety, including deciding which condition to prioritise, when to treat both conditions concurrently, and when psychological interventions or specialist input may be indicated.

5. Prescribe and optimise ADHD medication safely in patients with anxiety, understanding the potential effects of stimulant and non-stimulant medications on anxiety symptoms, selecting appropriate treatments, and recognising when medication adjustments are necessary.

6. Monitor treatment response and manage ongoing clinical complexity, including distinguishing medication-related anxiety from underlying anxiety disorders, evaluating changes in functioning, and adapting treatment plans through shared decision-making.

3. The Lecture

3.1 Understanding the Relationship Between ADHD and Anxiety

ADHD and anxiety are two of the most commonly encountered conditions in psychiatric practice, and they frequently coexist. For clinicians prescribing ADHD medication, understanding this relationship is essential because anxiety can influence diagnostic assessment, medication selection, titration, treatment adherence and long-term outcomes.

The first principle I would encourage you to remember is that anxiety in someone with ADHD is not necessarily an anxiety disorder.

Anxiety is a normal human response to uncertainty, perceived threat and stressful situations. It becomes clinically significant when it is excessive, persistent, difficult to control, or associated with substantial distress or functional impairment.

People with ADHD may experience considerable anxiety because of the difficulties associated with their ADHD symptoms. For example, someone who regularly forgets appointments, misses deadlines or struggles to complete tasks may develop persistent worries about making mistakes or disappointing others.

In these circumstances, anxiety may be understandable in the context of their everyday experiences rather than representing an independent anxiety disorder.

However, ADHD and anxiety disorders can also coexist as distinct conditions, each requiring assessment and potentially separate treatment.

The distinction is clinically important because the most appropriate intervention will depend on what is driving the patient's symptoms.

How Common Is Anxiety in ADHD?

Anxiety disorders are substantially more common in people with ADHD than in the general population.

Estimates vary according to age, diagnostic criteria and study population, but approximately one-quarter to one-half of individuals with ADHD may experience a coexisting anxiety disorder during their lifetime or at a particular point in their clinical course.

Common anxiety disorders encountered alongside ADHD include:

• Generalised anxiety disorder (GAD).

• Social anxiety disorder.

• Separation anxiety disorder, particularly in children.

• Panic disorder.

• Specific phobias.

• Agoraphobia.

Obsessive-compulsive disorder and post-traumatic stress disorder may also coexist with ADHD, although they are classified separately from anxiety disorders in DSM-5.

These distinctions matter because different conditions require different clinical formulations and treatment approaches.

For example, someone with ADHD and generalised anxiety disorder may benefit from ADHD medication alongside cognitive behavioural therapy (CBT) for persistent worry. Someone with ADHD and panic disorder may require a different approach, particularly if stimulant-related physical sensations are contributing to panic symptoms.

Why Do ADHD and Anxiety Frequently Coexist?

There is no single explanation for the association between ADHD and anxiety.

Several mechanisms are likely to contribute.

Shared vulnerability

ADHD and anxiety disorders have overlapping genetic and neurodevelopmental risk factors. Some individuals may therefore be predisposed to developing both conditions independently.

Consequences of ADHD symptoms

Executive functioning difficulties can create repeated experiences of stress, uncertainty and perceived failure.

A child who frequently forgets homework may become anxious about attending school. An adult who struggles to manage deadlines may develop persistent worries about losing their job.

Over time, these experiences can contribute to anxiety that extends beyond the original situations.

Emotional regulation difficulties

Many individuals with ADHD experience difficulties regulating emotional responses. They may become overwhelmed more quickly, struggle to recover from stressful experiences or find uncertainty particularly difficult to tolerate.

Although emotional dysregulation is not itself a core DSM-5 diagnostic criterion for ADHD, it is clinically relevant and may contribute to anxiety.

Environmental and interpersonal factors

Repeated criticism, academic difficulties, social misunderstandings and difficulties maintaining relationships can all increase vulnerability to anxiety.

These experiences are particularly relevant when ADHD has remained unrecognised or untreated for many years.

The important clinical point is that these mechanisms are not mutually exclusive. A patient may have a genuine anxiety disorder that is made considerably worse by poorly controlled ADHD.

3.2 Distinguishing ADHD Symptoms From Anxiety Symptoms

One of the most challenging aspects of assessment is that ADHD and anxiety can produce superficially similar presentations.

Both conditions may involve:

• Poor concentration.

• Restlessness.

• Irritability.

• Sleep difficulties.

• Difficulty completing tasks.

• Avoidance of demanding situations.

• Feeling overwhelmed.

• Reduced confidence.

If we rely on these symptoms alone, there is a considerable risk of diagnostic confusion.

Instead, we need to understand the underlying mechanism, developmental history and context in which the symptoms occur.

Difficulties With Concentration

Consider two patients who both describe being unable to concentrate during meetings.

The first patient explains that their attention drifts towards unrelated thoughts, surrounding conversations and environmental distractions. They have experienced similar difficulties since childhood, including during activities they enjoy.

The second patient explains that they cannot concentrate because they are repeatedly thinking about whether they will lose their job, whether colleagues dislike them and what might happen if they make a mistake.

Both patients have difficulties concentrating, but the underlying mechanisms may be different.

In ADHD, inattention is often associated with difficulties regulating attention, resisting distraction and maintaining effort.

In anxiety, concentration difficulties are frequently associated with attention being occupied by worry, threat monitoring or intrusive anxious thoughts.

Of course, a patient may experience both mechanisms simultaneously.

Clinical example

A 24-year-old university student describes difficulties concentrating during lectures.

Further questioning reveals that they have always struggled to maintain attention, frequently lost belongings and required considerable support with organisation throughout childhood.

However, they have also developed significant worries about academic failure during the previous year.

In this situation, ADHD may explain the longstanding attentional difficulties, while anxiety is contributing additional cognitive interference.

Treating the anxiety alone would not necessarily resolve the underlying ADHD symptoms.

Restlessness and Hyperactivity

Restlessness is another area of overlap.

A patient with ADHD may describe an internal sense of needing stimulation, difficulty sitting still, frequent fidgeting and a tendency to move between activities.

A patient with anxiety may describe restlessness associated with tension, apprehension and an inability to relax because they feel something bad might happen.

One useful question is:

"When you feel restless, is it because you need to be doing something, or because you feel worried or on edge?"

The answer will not establish the diagnosis by itself, but it may help clarify the experience.

Avoidance and Procrastination

Procrastination is frequently associated with ADHD, but it is also common in anxiety disorders.

In ADHD, procrastination may arise from difficulties initiating tasks, organising the necessary steps, estimating time or sustaining mental effort.

In anxiety, avoidance may be driven by fear of failure, embarrassment, uncertainty or anticipated distress.

For example, a patient may avoid opening emails because they struggle to organise and respond to them. Another may avoid opening emails because they fear receiving criticism.

Many patients experience both difficulties.

Understanding the reason for avoidance helps determine whether the intervention should focus primarily on executive functioning strategies, anxiety management or both.

The Importance of Developmental History

ADHD is a neurodevelopmental condition, and its symptoms should have been present during childhood, even if they were not recognised at the time.

Anxiety disorders can begin during childhood, adolescence or adulthood.

When assessing a patient with prominent anxiety symptoms, it is therefore important to establish whether difficulties with attention, organisation and impulsivity were present before the onset of clinically significant anxiety.

However, the presence of childhood anxiety does not exclude ADHD, and retrospective accounts may be affected by recall difficulties.

Collateral information, school reports and developmental history can be particularly helpful.

3.3 Recognising Anxiety Secondary to ADHD

In clinical practice, one of the most useful distinctions is between anxiety that appears largely secondary to ADHD-related difficulties and anxiety that represents an independent disorder.

This distinction is not always clear-cut, but it can guide treatment planning.

Anxiety Driven by Executive Functioning Difficulties

Imagine an adult with untreated ADHD who struggles to manage their workload.

They frequently forget tasks, underestimate how long work will take and leave important responsibilities until the last minute.

As deadlines approach, they become increasingly anxious.

They may begin checking their emails repeatedly, worrying about making mistakes and struggling to sleep before important meetings.

Their anxiety is real and potentially very distressing.

However, much of it may be driven by the consequences of untreated ADHD.

If effective ADHD treatment improves their ability to organise tasks, meet deadlines and manage responsibilities, their anxiety may improve substantially without requiring separate pharmacological treatment.

This is one reason why we should not automatically assume that stimulant medication will worsen anxiety.

Anxiety Associated With Repeated Negative Experiences

Some patients develop anxiety following years of criticism, perceived failure or difficulties meeting expectations.

For example, a child with ADHD may repeatedly receive negative feedback for forgetting equipment, interrupting lessons or failing to complete work.

Over time, they may become increasingly anxious about attending school or making mistakes.

In adulthood, similar experiences can contribute to perfectionism, avoidance and persistent self-doubt.

Medication may improve ADHD symptoms, but psychological interventions may still be required to address established patterns of anxiety and negative beliefs.

When Anxiety Is More Likely to Be Independent

Features suggesting a coexisting anxiety disorder include:

• Excessive worry extending across multiple areas of life.

• Anxiety that persists even when ADHD-related demands are well managed.

• Recurrent panic attacks.

• Marked social fears associated with negative evaluation.

• Significant phobic avoidance.

• Anxiety symptoms that are disproportionate to the immediate circumstances.

• Persistent anxiety that causes impairment independently of ADHD symptoms.

These features should prompt a structured assessment rather than simply attributing anxiety to ADHD.

Clinical pearl: A useful question is whether the anxiety would still be clinically significant if the patient's ADHD symptoms were substantially better controlled.

This is not a definitive diagnostic test, but it can help develop a formulation.

3.4 Assessing Anxiety in Patients With ADHD

Before prescribing ADHD medication, clinicians should assess relevant coexisting mental health conditions, including anxiety.

This is particularly important when anxiety is severe, recently deteriorating or associated with substantial functional impairment.

Establishing the Nature of the Anxiety

Begin by asking the patient to describe their anxiety in their own words.

Useful questions include:

• What do you tend to worry about?

• When did the anxiety first become a problem?

• Is the anxiety present most days or only in particular situations?

• Do you experience physical symptoms such as palpitations, trembling or sweating?

• Are there situations you avoid because of anxiety?

• Does the anxiety interfere with sleep, work, education or relationships?

• Have you experienced panic attacks?

• What happens to your anxiety when your ADHD symptoms are better controlled?

The aim is to understand the pattern of symptoms rather than simply establish whether the patient feels anxious.

Identifying Specific Anxiety Disorders

Generalised anxiety disorder typically involves excessive worry across multiple areas of life, difficulty controlling worry and associated symptoms such as restlessness, fatigue, irritability, muscle tension, sleep disturbance and concentration difficulties.

Social anxiety disorder involves marked fear of social situations in which the individual may be scrutinised or negatively evaluated.

Panic disorder involves recurrent unexpected panic attacks and persistent concern or behavioural changes associated with further attacks.

Separation anxiety disorder may be particularly relevant in children and young people who experience excessive distress when separated from attachment figures.

Specific phobias involve marked fear or anxiety associated with particular objects or situations.

Accurate identification matters because treatment should address the specific condition rather than treating anxiety as a single undifferentiated symptom.

Assessing Severity and Functional Impact

It is important to establish how much the anxiety affects the patient's everyday functioning.

Someone may describe frequent worries but remain able to attend school, work and maintain relationships.

Another patient may experience severe avoidance, significant sleep disturbance or an inability to leave home.

The severity of anxiety will influence treatment priorities.

Standardised measures can support assessment and monitoring.

For adults, the GAD-7 may be useful for quantifying general anxiety symptoms.

For children and adolescents, instruments such as the Revised Children's Anxiety and Depression Scale (RCADS) may provide additional information.

However, these measures do not replace clinical assessment or establish a specific diagnosis independently.

Assessing Risk and Differential Diagnoses

A comprehensive assessment should also consider:

• Depression and suicidal ideation.

• Self-harm.

• Substance and alcohol use.

• Trauma-related symptoms.

• Obsessive-compulsive symptoms.

• Sleep disorders.

• Autism and sensory-related distress.

• Bipolar disorder where clinically indicated.

• Physical conditions that may contribute to anxiety symptoms, such as thyroid dysfunction or cardiac arrhythmias.

• Medication and substance effects, including caffeine, stimulants and other sympathomimetic agents.

Particular attention should be given to patients describing palpitations, chest discomfort or marked autonomic symptoms, especially when considering stimulant medication.

These symptoms should not automatically be attributed to anxiety without an appropriate clinical assessment.

3.5 Deciding Which Condition to Treat First

A common question in clinical practice is whether ADHD or anxiety should be treated first.

There is no single approach that is appropriate for every patient.

The decision should be based on symptom severity, functional impairment, clinical risk, patient preference and the relationship between the two conditions.

When ADHD May Be the Initial Treatment Priority

If ADHD symptoms are the principal cause of impairment and anxiety appears largely related to the consequences of ADHD, treating ADHD first may be appropriate.

For example, an adult may experience significant anxiety because they repeatedly miss deadlines and struggle to manage responsibilities.

If their anxiety is primarily associated with these difficulties, improving ADHD symptoms may reduce the situations generating anxiety.

In this situation, ADHD medication can be started with appropriate monitoring.

The clinician should explain that anxiety may improve, remain unchanged or occasionally worsen during treatment.

When Anxiety May Need to Be Prioritised

If anxiety is severe, highly impairing or preventing meaningful engagement with ADHD treatment, it may be appropriate to address anxiety first or concurrently.

Examples include:

• Severe panic disorder with substantial avoidance.

• Anxiety preventing school attendance or leaving home.

• Severe generalised anxiety associated with marked sleep disturbance.

• Significant anxiety accompanied by depression or safety concerns.

However, even in these circumstances, treating anxiety first is not an absolute requirement.

The clinical decision should consider whether untreated ADHD is maintaining the anxiety and whether simultaneous interventions would be more effective.

When Both Conditions Should Be Treated Together

Many patients benefit from a combined approach.

For example, a patient with ADHD and social anxiety disorder may require medication to improve attention and impulsivity alongside CBT targeting fears of negative evaluation.

Treating ADHD alone may not resolve the social anxiety disorder.

Similarly, treating social anxiety alone may not address longstanding executive functioning difficulties.

The most useful approach is often to identify the principal mechanisms maintaining impairment and develop a treatment plan addressing both.

3.6 Stimulant Medication in Patients With Anxiety

One of the most persistent misconceptions in ADHD prescribing is that stimulant medication should generally be avoided when anxiety is present.

This is not supported by current clinical guidance.

NICE guideline NG87 recommends offering people with ADHD and an anxiety disorder the same ADHD medication choices as other people with ADHD.

This is an important principle.

Anxiety is not, by itself, a contraindication to stimulant medication.

However, the presence of anxiety may influence how medication is initiated, titrated and monitored.

Can Stimulants Improve Anxiety?

Yes, in some patients.

Effective stimulant treatment can improve attention, organisation, task initiation and impulse control.

These improvements may reduce stress and anxiety associated with everyday functioning.

For example, a patient who previously felt overwhelmed by work may become more organised and able to complete responsibilities.

As a result, they may feel more confident and less anxious.

A meta-analysis of randomised controlled trials in children with ADHD found that psychostimulant treatment was associated with a lower reported risk of anxiety than placebo.

This is reassuring, although it does not mean stimulants are anxiolytic treatments or that every patient will experience an improvement.

Can Stimulants Worsen Anxiety?

Yes.

Some patients experience increased anxiety, nervousness, irritability or physical tension during stimulant treatment.

This may be particularly apparent during initiation or following dose increases.

Potential mechanisms include:

• Increased physiological arousal.

• Sleep disruption.

• Reduced appetite and associated physical discomfort.

• Excessive stimulant exposure.

• Increased awareness of bodily sensations.

• Rebound symptoms as medication effects wear off.

It is therefore important to distinguish worsening of an underlying anxiety disorder from medication-related adverse effects.

Distinguishing Medication-Related Anxiety

The timing of symptoms is particularly useful.

If anxiety consistently develops shortly after taking medication, becomes more prominent following dose increases and improves as the medication wears off, a medication-related contribution should be considered.

Conversely, if anxiety is present throughout the day, occurs on medication-free days and predates treatment, an underlying anxiety disorder may be more likely.

However, these patterns are not definitive.

Anxiety emerging in the afternoon may reflect medication wearing off, but it may also be related to school demands, fatigue or other environmental factors.

A careful history is required.

Practical Prescribing Approach

For patients with clinically significant anxiety, it is often sensible to:

1. Establish baseline anxiety symptoms before starting medication.

2. Explain the possible effects of treatment on anxiety.

3. Start at an appropriate low dose.

4. Titrate according to clinical response and tolerability.

5. Monitor anxiety, sleep, appetite and cardiovascular observations.

6. Review whether anxiety changes in relation to medication timing.

7. Adjust the treatment plan if anxiety becomes clinically problematic.

NICE advises slower titration and more frequent monitoring when relevant coexisting mental health conditions, including anxiety disorders, are present.

This does not mean that every anxious patient requires unusually prolonged titration, but clinicians should avoid unnecessary rapid dose escalation.

Clinical Example

A 16-year-old with ADHD and generalised anxiety disorder starts modified-release methylphenidate.

At the initial review, they describe improved concentration and less anxiety about schoolwork.

However, following a dose increase, they develop increased nervousness and difficulty sleeping.

Rather than immediately concluding that stimulant treatment is unsuitable, the clinician should explore the timing of symptoms, sleep, caffeine intake, changes in school demands and whether the higher dose provides additional ADHD benefit.

If the deterioration appears dose-related, returning to the previously tolerated dose may be appropriate.

The aim is to identify the dose providing the best balance between symptom improvement and adverse effects.

3.7 Non-Stimulant Medication and Anxiety

Non-stimulant medications are sometimes considered when ADHD and anxiety coexist.

However, it is important not to assume that non-stimulants are always preferable in patients with anxiety.

Atomoxetine

Atomoxetine is a selective noradrenaline reuptake inhibitor used in ADHD treatment.

It may be particularly useful when stimulants are ineffective, poorly tolerated or otherwise unsuitable.

Research suggests that atomoxetine can improve ADHD symptoms in patients with coexisting anxiety disorders and generally does not worsen anxiety. Some studies have also demonstrated improvements in anxiety symptoms.

However, atomoxetine is not licensed as a primary treatment for anxiety disorders.

Its potential benefits for anxiety should therefore be considered in the context of treating ADHD rather than as a replacement for evidence-based anxiety treatment.

Atomoxetine may also produce adverse effects such as nausea, reduced appetite, sleep disturbance, increased heart rate or increased blood pressure.

Some patients experience activation or increased anxiety, particularly during early treatment.

Monitoring remains essential.

Guanfacine

Guanfacine is an alpha-2A adrenergic receptor agonist used in ADHD treatment.

It may be considered in children and young people when stimulant medication is unsuitable or ineffective, according to relevant prescribing guidance.

Because guanfacine reduces sympathetic outflow, it can produce sedation and reductions in heart rate and blood pressure.

However, this should not be interpreted as evidence that it is an established treatment for anxiety disorders.

Evidence supporting guanfacine specifically for anxiety in patients with ADHD is limited.

In UK practice, guanfacine is not routinely recommended for adult ADHD without appropriate specialist advice.

Choosing Between Stimulants and Non-Stimulants

Medication selection should consider:

• Previous treatment response.

• Severity and nature of anxiety.

• ADHD symptom profile.

• Adverse effect vulnerability.

• Sleep difficulties.

• Cardiovascular history.

• Patient preferences.

• Relevant NICE recommendations.

• Licensing and specialist prescribing requirements.

The presence of anxiety alone should not automatically determine medication selection.

For many patients, methylphenidate or lisdexamfetamine remains an appropriate option.

3.8 Treating Anxiety Alongside ADHD

When a patient has an independent anxiety disorder, treatment should follow established evidence-based guidance for that condition.

ADHD medication may reduce some anxiety-related difficulties, but it should not be expected to resolve every anxiety disorder.

Psychological Interventions

Cognitive behavioural therapy is an established treatment for several anxiety disorders.

CBT may include:

• Identifying and modifying unhelpful patterns of thinking.

• Gradual exposure to feared situations.

• Reducing avoidance and safety behaviours.

• Developing strategies for managing worry.

• Improving tolerance of uncertainty.

• Addressing anxiety-related beliefs and behavioural patterns.

However, standard CBT may need adaptation for patients with ADHD.

Someone with significant executive functioning difficulties may struggle with lengthy homework assignments, remembering between-session tasks or maintaining attention during therapy.

Practical adaptations may include shorter tasks, written reminders, structured sessions, repetition and support with implementing strategies.

These adaptations can improve accessibility without changing the fundamental principles of treatment.

Pharmacological Treatment of Anxiety

For some patients, psychological treatment alone may not be sufficient or may not be preferred.

Selective serotonin reuptake inhibitors (SSRIs) are commonly used in the treatment of several anxiety disorders, depending on the specific diagnosis, age and relevant clinical guidance.

For adults with generalised anxiety disorder, NICE recommends considering an SSRI when medication treatment is appropriate, with sertraline identified as an initial option, subject to licensing considerations.

For children and young people, medication decisions require greater caution and should follow disorder-specific guidance.

For example, NICE recommends psychological treatment as the primary intervention for social anxiety disorder in children and young people, rather than routinely offering medication.

Combining SSRIs With ADHD Medication

In some patients, an SSRI and ADHD medication may be prescribed together.

This can be appropriate when both conditions require pharmacological treatment.

However, the combination requires careful consideration of:

• Potential drug interactions.

• Activation or agitation.

• Sleep disturbance.

• Cardiovascular effects.

• Suicidal thoughts or behavioural changes, particularly in younger patients.

• Serotonergic adverse effects where relevant.

Some SSRIs, particularly fluoxetine and paroxetine, inhibit CYP2D6 and can substantially increase atomoxetine exposure.

This interaction may require atomoxetine dose adjustments and closer monitoring in accordance with the product information.

Although stimulant–SSRI combinations are used clinically, prescribers should review the specific medications rather than assuming that all combinations carry identical risks.

Avoiding Unnecessary Polypharmacy

A patient who remains anxious after starting ADHD medication does not automatically require an SSRI.

Before adding another medication, consider whether the anxiety is related to:

• Excessive stimulant dosage.

• Poor sleep.

• Rebound symptoms.

• Caffeine or other substances.

• Persistent ADHD impairment.

• Environmental stress.

• An independently diagnosable anxiety disorder.

Medication should be added when there is a clear clinical indication, rather than simply in response to a symptom that has not yet been adequately formulated.

3.9 ADHD, Anxiety and Sleep

Sleep difficulties are particularly common in patients with ADHD and anxiety.

The relationship can become self-perpetuating.

ADHD may contribute to difficulties maintaining routines, disengaging from stimulating activities and settling at bedtime.

Anxiety may contribute to excessive worry, anticipatory thinking and physiological arousal.

Poor sleep can then worsen attention, irritability, emotional regulation and anxiety the following day.

Assessing Sleep Before Changing Medication

When a patient reports worsening anxiety during ADHD treatment, sleep should be reviewed carefully.

Ask about:

• Bedtime and waking time.

• Sleep onset latency.

• Night-time awakenings.

• Evening worry.

• Caffeine intake.

• Medication timing.

• Screen use and bedtime routines.

• Daytime fatigue.

• Snoring or symptoms suggesting another sleep disorder.

A patient who is sleeping only four or five hours each night may experience considerable anxiety and emotional instability.

Increasing ADHD medication without addressing the sleep disturbance may worsen the situation.

Medication Timing

Long-acting stimulant preparations can sometimes interfere with sleep, particularly when taken too late in the day or when their duration of effect extends into the evening.

However, some patients sleep better when ADHD symptoms are adequately controlled.

The relationship is therefore individual.

Treatment adjustments should be guided by the patient's actual sleep pattern rather than assumptions about how stimulants affect sleep.

3.10 Monitoring Anxiety During ADHD Treatment

Monitoring should involve more than asking whether the patient feels more or less anxious.

The clinician should assess the relationship between ADHD symptoms, anxiety, functioning and adverse effects.

Establishing a Baseline

Before starting treatment, document:

• The nature and severity of anxiety symptoms.

• Relevant anxiety diagnoses.

• Functional impairment.

• Sleep quality.

• Physical symptoms associated with anxiety.

• Current psychological or pharmacological treatments.

• Relevant risk factors.

This makes it easier to interpret changes during treatment.

Reviewing Response During Titration

At follow-up appointments, consider:

ADHD symptoms: Have attention, organisation, impulsivity or hyperactivity improved?

Anxiety symptoms: Has worry, avoidance, panic or physical tension changed?

Timing: Are symptoms associated with medication onset, peak effect or wearing off?

Functioning: Is the patient managing school, work, relationships and daily responsibilities more effectively?

Adverse effects: Are sleep disturbance, appetite suppression or physical symptoms contributing to anxiety?

Patient experience: Does the patient feel that the overall balance of benefits and disadvantages is acceptable?

The most useful outcome is not necessarily the lowest anxiety score or the greatest reduction in ADHD symptoms considered separately.

It is meaningful improvement in the patient's overall functioning and quality of life.

When Anxiety Worsens During Treatment

If anxiety becomes more prominent, the clinician should first determine whether there is an immediate safety concern or a potentially serious adverse effect.

New chest pain, significant palpitations, syncope or other concerning cardiovascular symptoms require appropriate medical assessment rather than being assumed to represent anxiety.

If the deterioration appears related to medication and there are no urgent concerns, options may include:

• Reviewing the dose.

• Adjusting medication timing.

• Returning to a previously tolerated dose.

• Considering an alternative formulation.

• Considering another ADHD medication.

• Providing or arranging targeted anxiety treatment.

The decision should be based on the overall clinical picture.

3.11 Special Considerations in Children and Young People

ADHD and anxiety frequently coexist in children and adolescents, but the presentation may differ from that seen in adults.

Children may struggle to describe internal worries and instead present with behavioural or physical symptoms.

Examples include:

• School refusal or difficulty attending school.

• Frequent reassurance seeking.

• Irritability.

• Tearfulness.

• Abdominal pain or headaches.

• Difficulty separating from caregivers.

• Sleep disturbance.

• Avoidance of social situations.

It is important not to interpret every behavioural difficulty as a direct consequence of ADHD.

School-Related Anxiety

A child with ADHD may become anxious about school because they struggle academically, experience social difficulties or receive frequent negative feedback.

However, school-related anxiety may also arise from bullying, learning difficulties, sensory overload, family circumstances or an independent anxiety disorder.

A comprehensive assessment should explore these possibilities.

For example, increasing stimulant medication is unlikely to resolve school refusal primarily driven by bullying or severe separation anxiety.

Working With Families

Parents and caregivers can provide valuable information about symptom patterns, medication response and functional changes.

However, the child's own experience remains important.

A parent may describe substantial improvement in behaviour while the child reports feeling more tense or emotionally uncomfortable.

Both perspectives should be explored.

Similarly, a child may appear calmer at school but experience significant anxiety after returning home.

Information from different settings can help identify these patterns.

Avoiding Overinterpretation of Behaviour

An anxious child may appear oppositional when asked to engage in a feared activity.

A child with ADHD may avoid tasks because of executive functioning difficulties.

A child with both conditions may experience several mechanisms simultaneously.

The clinical task is to understand the function of the behaviour rather than rely solely on its outward appearance.

3.12 Clinical Case Discussion

Consider the following clinical scenario.

A 15-year-old girl has recently been diagnosed with ADHD, predominantly inattentive presentation.

She describes longstanding difficulties with concentration, organisation, completing homework and remembering instructions.

Over the previous two years, she has developed increasing anxiety about school performance.

She worries excessively about failing examinations, frequently seeks reassurance from her parents and struggles to sleep before school.

Her family are concerned that stimulant medication may make her anxiety worse.

Step 1: Clarify the Relationship Between ADHD and Anxiety

The first task is to establish whether her anxiety is primarily associated with ADHD-related academic difficulties or whether she also meets diagnostic criteria for an anxiety disorder.

Further assessment reveals that she worries about multiple areas of life, including family members becoming unwell, friendships and everyday situations unrelated to school.

This suggests that a coexisting anxiety disorder may be present.

Step 2: Assess Severity and Risk

The clinician explores the degree of impairment, sleep difficulties, school attendance, depressive symptoms and any self-harm or suicidal thoughts.

Her anxiety is moderately impairing, but she continues to attend school and engage with daily activities.

There are no immediate safety concerns.

Step 3: Develop a Treatment Plan

Because ADHD symptoms are longstanding and significantly affecting her academic functioning, it may be reasonable to begin ADHD medication while also arranging an appropriate psychological intervention for anxiety.

The presence of anxiety does not automatically exclude methylphenidate.

The clinician explains the potential benefits and adverse effects and agrees a cautious titration plan.

Step 4: Monitor the Response

After starting modified-release methylphenidate, she describes improved concentration and greater confidence in completing schoolwork.

Her anxiety about academic performance reduces.

However, she continues to experience worries about family members and friendships.

This suggests that treating ADHD has improved some anxiety-related difficulties, while an independent anxiety problem remains.

Step 5: Address Residual Anxiety

The clinician continues to optimise ADHD treatment and supports access to CBT for the ongoing anxiety.

An SSRI is not automatically required, particularly where psychological treatment is appropriate and acceptable.

Further treatment decisions depend on the severity of persistent symptoms, response to psychological intervention and relevant guidance for her age and diagnosis.

What Does This Case Teach Us?

The important lesson is that anxiety and ADHD should not be viewed as competing diagnoses.

Both conditions may contribute to impairment, and improving one may partially improve the other.

Effective management requires an individualised formulation rather than a rigid rule that anxiety must always be treated before ADHD.

3.13 Bringing the Clinical Principles Together

When assessing a patient with ADHD and anxiety, I would encourage you to think through five questions.

First, what is the nature of the anxiety?

Is it persistent worry, panic, social fear, avoidance, physical tension or something else?

Second, what is driving the anxiety?

Is it largely associated with ADHD-related difficulties, an independent anxiety disorder, medication effects or several interacting factors?

Third, which symptoms are causing the greatest impairment?

This helps determine treatment priorities.

Fourth, how might ADHD treatment influence the anxiety?

Medication may reduce anxiety through improved functioning, but adverse effects or increased physiological arousal can occasionally worsen symptoms.

Finally, how will we know whether treatment is working?

Monitoring should consider both conditions, overall functioning, patient experience and adverse effects.

The central prescribing principle is that anxiety should influence how we assess, individualise and monitor ADHD treatment, but it should not automatically prevent us from treating ADHD effectively.

For many patients, recognising and treating both conditions can produce substantial improvements in functioning, confidence and quality of life.

4. Clinical Perspective

Managing ADHD alongside anxiety requires careful clinical judgement. Although guidelines provide a useful framework, everyday practice is rarely as straightforward as deciding whether a patient has one diagnosis or two. Anxiety can arise from untreated ADHD, coexist as an independent disorder, or occasionally emerge as an adverse effect of medication.

The most important skill for the prescribing clinician is learning to understand the relationship between these difficulties rather than treating each symptom in isolation.

4.1 Clinical Pearls

Anxiety Is Not a Contraindication to Stimulant Medication

One of the most common misconceptions among clinicians is that patients with anxiety should not receive stimulant medication.

In practice, this can lead to patients being denied effective ADHD treatment unnecessarily.

NICE guidance recommends the same ADHD medication choices for patients with coexisting anxiety disorders as for other patients with ADHD.

Indeed, some patients experience substantial improvements in anxiety once their ADHD is adequately treated.

Consider an adult who has spent years worrying about missed deadlines, forgotten responsibilities and difficulties managing everyday life. Once medication improves their executive functioning, many of the situations generating anxiety may become more manageable.

However, this does not mean that stimulants invariably improve anxiety. Some patients experience increased nervousness, physiological arousal or sleep disturbance.

The clinical lesson is to assess and monitor anxiety carefully rather than automatically avoiding stimulant medication.

Treat the Underlying Difficulty, Not Just the Presenting Symptom

Patients frequently describe feeling anxious, overwhelmed or unable to cope.

However, the word anxiety does not necessarily identify the underlying problem.

A patient who becomes anxious whenever they need to complete administrative tasks may primarily be struggling with task initiation and organisation.

Another patient may avoid the same tasks because they fear making mistakes or receiving criticism.

Although the outward presentation may be similar, the treatment approaches may differ considerably.

Before prescribing medication for anxiety, establish what the patient is actually experiencing and why.

Improvement in ADHD Can Reveal Residual Anxiety

Occasionally, patients become more aware of their anxiety after ADHD symptoms improve.

Previously, their attention may have been dominated by distraction, disorganisation and impulsivity. Once these symptoms become more manageable, persistent worries or social fears may become more apparent.

This does not necessarily mean that ADHD medication has caused anxiety.

It may simply mean that an independent anxiety disorder is now easier to recognise.

The distinction is particularly important when anxiety is reported during medication titration.

The Timing of Anxiety Symptoms Is Often More Informative Than Their Severity

When a patient reports increased anxiety after starting medication, establish exactly when it occurs.

Does it begin shortly after taking the medication? Does it coincide with the expected peak effect? Does it appear as the medication wears off? Is it present on days when medication is not taken?

A clear relationship with medication timing may suggest an adverse effect or rebound phenomenon.

Anxiety that is persistent across different circumstances may be more consistent with an underlying anxiety disorder.

However, timing alone cannot establish causation. School demands, workplace pressures, sleep and environmental factors must also be considered.

4.2 Practical Tips for Everyday Prescribing

Establish Baseline Anxiety Before Starting Medication

A common difficulty during titration is that patients report feeling more anxious, but neither the patient nor clinician can clearly remember how anxious they were before treatment.

This makes it difficult to determine whether the medication has genuinely worsened symptoms.

Before starting ADHD medication, document the patient's existing anxiety symptoms, their frequency, severity and impact on functioning.

It is particularly helpful to establish whether they experience panic attacks, persistent worry, social avoidance, sleep difficulties or physical symptoms of anxiety.

Standardised measures such as the GAD-7 can be useful for adults, although they should supplement rather than replace clinical assessment.

Explain That Anxiety May Improve or Worsen

When discussing medication with patients, avoid presenting the effects on anxiety as entirely predictable.

A balanced explanation might be that ADHD medication can reduce anxiety when it improves organisation, attention and everyday functioning, but some people experience increased nervousness or physical tension.

Patients should understand what changes to monitor and when to contact the prescribing team.

This is particularly important for patients who are already apprehensive about medication.

Avoid Increasing Medication Simply Because the Patient Remains Overwhelmed

A patient may report that they continue to feel overwhelmed despite improvements in attention and concentration.

It can be tempting to interpret this as evidence that the ADHD medication dose is insufficient.

However, feeling overwhelmed may reflect persistent anxiety, environmental demands, poor sleep or emotional regulation difficulties.

Before increasing the dose, establish whether core ADHD symptoms remain inadequately controlled.

If attention and organisation have improved substantially but excessive worry persists, increasing the stimulant may provide little additional benefit and could worsen adverse effects.

Consider Sleep Before Making Medication Changes

Sleep disturbance is a frequent contributor to both anxiety and ADHD symptoms.

When a patient describes increased irritability, emotional sensitivity or anxiety, establish whether they are sleeping adequately.

Poor sleep can produce symptoms that resemble worsening ADHD, anxiety or medication intolerance.

Sometimes, reviewing medication timing, sleep routines and other contributors to insomnia is more useful than changing the medication itself.

Use Functional Outcomes to Guide Treatment

Symptom reduction is important, but improvement in everyday functioning should remain central to treatment decisions.

For example, a patient may continue to experience some anxiety but become significantly more able to attend school, complete work, manage relationships and participate in daily activities.

Conversely, a patient may describe improved concentration while experiencing such severe anxiety that their overall functioning deteriorates.

Successful treatment requires a reasonable balance between symptom improvement, adverse effects and quality of life.

4.3 Common Pitfalls and Misconceptions

Assuming All Anxiety Is Secondary to ADHD

Although untreated ADHD can contribute to anxiety, not every anxious symptom can be explained by executive functioning difficulties.

Patients may have generalised anxiety disorder, social anxiety disorder, panic disorder or other clinically significant conditions.

If anxiety is persistent, excessive and independently impairing, it deserves assessment in its own right.

Failure to recognise comorbidity can result in patients receiving increasingly high doses of ADHD medication while their anxiety remains untreated.

Assuming All Anxiety During Titration Is Caused by Medication

The opposite error is equally common.

A patient may report increased anxiety after starting medication, leading the clinician to conclude that the medication is unsuitable.

However, anxiety naturally fluctuates, particularly in response to school examinations, workplace pressures, family difficulties and changes in routine.

A temporal association does not necessarily establish a causal relationship.

Review the symptom pattern, medication timing, dose changes and external circumstances before making treatment decisions.

Automatically Choosing Atomoxetine Because Anxiety Is Present

Atomoxetine can be a useful medication for ADHD, including in patients with coexisting anxiety.

However, anxiety alone is not a reason to avoid stimulants or automatically select atomoxetine.

Medication choice should be based on clinical presentation, previous response, tolerability, patient preference and relevant prescribing guidance.

Atomoxetine may also cause adverse effects, including sleep disturbance and increased physiological arousal, so it should not be regarded as universally calming.

Prescribing an SSRI Without Establishing an Anxiety Disorder

Patients with ADHD may experience anxiety-related distress without meeting criteria for an independent anxiety disorder.

Adding an SSRI simply because a patient feels anxious can result in unnecessary polypharmacy.

Before prescribing, clarify the diagnosis, severity, functional impact and available psychological interventions.

Where an anxiety disorder is present, treatment should follow the relevant disorder-specific guidance.

Overlooking Physical Symptoms

Palpitations, chest discomfort, dizziness and breathlessness can occur during anxiety or panic attacks.

However, these symptoms should not automatically be attributed to anxiety, particularly in patients receiving stimulant medication.

New or concerning cardiovascular symptoms require appropriate medical assessment.

If a patient develops chest pain, significant palpitations, syncope or other symptoms suggesting a potentially serious cardiovascular problem, urgent assessment may be necessary. Stimulant treatment should be withheld when a serious medication-related cardiovascular problem is suspected, pending appropriate evaluation.

Clinical reassurance should follow assessment rather than replace it.

4.4 Advice for Newly Qualified Prescribers

Do Not Feel That Every Symptom Needs Immediate Pharmacological Treatment

New prescribers may feel pressure to resolve every difficulty described during an appointment.

However, effective prescribing sometimes involves recognising that medication is not the most appropriate intervention for a particular symptom.

A patient with ADHD may benefit from medication for attention and organisation while requiring CBT, environmental adjustments or practical support for anxiety.

The aim is not to prescribe a medication for every symptom, but to develop a coherent treatment plan.

Make One Medication Change at a Time Where Possible

When ADHD and anxiety coexist, it may be necessary to prescribe more than one medication.

However, starting or increasing several medications simultaneously can make it difficult to identify which treatment is responsible for improvement or adverse effects.

Where clinically appropriate, introduce changes sequentially and document the rationale.

There will be situations where concurrent treatment is necessary, particularly when both conditions are significantly impairing. In these circumstances, closer monitoring becomes especially important.

Be Cautious About Rapid Titration

Patients with anxiety may be particularly sensitive to changes in physical sensations, sleep or perceived medication effects.

NICE recommends slower titration and more frequent monitoring when relevant coexisting mental health conditions are present.

This does not mean that treatment should be unnecessarily delayed, but dose increases should be guided by demonstrated benefit and tolerability.

Ask About the Patient's Experience, Not Just Observable Behaviour

A parent may report that their child is calmer and more focused after starting medication.

However, the child may describe feeling tense, worried or uncomfortable.

Similarly, an adult may appear more organised at work while experiencing significant internal distress.

Observable improvement does not necessarily mean that the overall treatment experience is positive.

The patient's subjective experience should always form part of the medication review.

Know When to Seek Senior Advice

Seek supervision when the clinical presentation is unclear, anxiety is severe, medication responses are unusual or there are significant safety concerns.

Particular caution is warranted when anxiety occurs alongside severe depression, suicidal ideation, suspected bipolar disorder, substance misuse or concerning physical symptoms.

Seeking advice is part of safe clinical practice, particularly when managing complex comorbidity.

4.5 Situations Requiring Particular Clinical Judgement

Severe Anxiety Before Starting ADHD Medication

A patient presents with clear ADHD symptoms but also experiences severe anxiety, frequent panic attacks and substantial avoidance.

Should ADHD medication be started immediately?

There is no universal answer.

If ADHD is contributing significantly to the anxiety, effective treatment may improve both conditions.

However, if anxiety is so severe that the patient cannot engage with treatment or tolerate changes in physiological sensations, addressing the anxiety first or concurrently may be more appropriate.

The decision should consider clinical risk, functional impairment, patient preference and the likely relationship between the conditions.

Anxiety Following a Stimulant Dose Increase

A patient has been responding well to methylphenidate but develops increased anxiety after a dose increase.

In this situation, first establish whether the higher dose has produced additional ADHD benefit.

If there has been little improvement in ADHD symptoms but a clear increase in anxiety, returning to the previously tolerated dose may be reasonable.

If the higher dose has produced substantial functional improvement, consider whether anxiety is transient, related to sleep or another factor, or represents a clinically significant adverse effect.

The goal is not to reach the highest possible dose. It is to identify the most effective and tolerable regimen.

Persistent Anxiety Despite Good ADHD Control

A patient has achieved substantial improvement in attention, organisation and impulsivity but continues to experience excessive worry and avoidance.

At this stage, further ADHD medication escalation is unlikely to be the most appropriate response if core ADHD symptoms are already adequately controlled.

The clinician should reassess the anxiety and consider evidence-based psychological or pharmacological treatment where indicated.

This is a common situation in which recognising a separate anxiety disorder can significantly improve outcomes.

A Child Whose Anxiety Appears as Behavioural Dysregulation

A child with ADHD becomes distressed, irritable or oppositional when asked to attend school.

It may be tempting to interpret this as worsening impulsivity or emotional dysregulation associated with ADHD.

However, the behaviour may be driven by anxiety about separation, social interactions, academic demands or bullying.

Before increasing medication, explore what the child is experiencing and what the behaviour may be communicating.

Understanding the underlying difficulty is essential to choosing an effective intervention.

Patients Who Are Highly Anxious About Taking Medication

Some patients are particularly concerned about potential adverse effects and may monitor every physical sensation after starting treatment.

This can create difficulties in distinguishing expected physiological changes, anxiety-related symptoms and genuine medication intolerance.

A clear explanation of potential adverse effects, agreed monitoring arrangements and a gradual titration plan can help.

However, clinicians should avoid dismissing reported symptoms as psychological simply because the patient is anxious.

Each concern should be assessed on its clinical merits.

4.6 Final Clinical Reflection

The most effective clinicians do not approach ADHD and anxiety as two entirely separate problems, nor do they assume that one diagnosis explains everything.

Instead, they develop an individualised understanding of how symptoms interact.

For some patients, untreated ADHD is the principal driver of anxiety, and effective ADHD treatment produces substantial improvement.

For others, anxiety is an independent and persistent condition requiring targeted intervention.

For a smaller group, ADHD medication may contribute to increased anxiety, requiring adjustments to dose, formulation or medication choice.

The key is to remain curious, assess carefully and avoid rigid assumptions.

The presence of anxiety should prompt thoughtful prescribing, not therapeutic avoidance.

Ultimately, successful treatment is not simply about reducing ADHD symptoms or anxiety scores. It is about helping patients function more effectively, experience less distress and achieve meaningful improvements in their everyday lives.

5. Summary

ADHD and anxiety frequently coexist, and understanding the relationship between them is essential for safe and effective prescribing. Anxiety may represent an independent psychiatric disorder, develop as a consequence of ADHD-related difficulties, or occasionally emerge or worsen during medication treatment.

The key learning points from this lesson are:

1. ADHD and anxiety commonly coexist. Anxiety disorders are substantially more prevalent in individuals with ADHD than in the general population. Both conditions can contribute independently to functional impairment and reduced quality of life.

2. ADHD and anxiety share several clinical features. Difficulties with concentration, restlessness, irritability, sleep disturbance and avoidance can occur in both conditions. Careful assessment of developmental history, symptom patterns and underlying mechanisms is necessary to distinguish them.

3. Anxiety may be secondary to untreated ADHD. Repeated difficulties with organisation, deadlines, academic performance and relationships can contribute to persistent worry and stress. Effective ADHD treatment may reduce anxiety by improving everyday functioning.

4. Anxiety disorders must be recognised and assessed independently. Persistent excessive worry, panic attacks, social fears and significant avoidance may indicate a coexisting anxiety disorder requiring targeted treatment.

5. Anxiety is not a contraindication to stimulant medication. NICE recommends the same ADHD medication choices for patients with coexisting anxiety disorders as for other patients with ADHD. Stimulants may improve anxiety indirectly through better ADHD control, although some patients experience increased anxiety or physiological arousal.

6. Medication selection and titration should be individualised. Stimulants and non-stimulants may both be appropriate depending on the clinical circumstances. Coexisting anxiety disorders warrant careful titration and more frequent monitoring, particularly when symptoms are severe or medication tolerability is uncertain.

7. Treatment priorities depend on clinical severity and functional impairment. ADHD may be treated first when its symptoms are the principal driver of anxiety. Where an independent anxiety disorder causes significant impairment, psychological treatment, pharmacological treatment or a combined approach may be required.

8. Psychological interventions remain important. Cognitive behavioural therapy is an established treatment for several anxiety disorders and may require practical adaptations for individuals with ADHD. SSRIs may also be appropriate for particular anxiety disorders, according to age, diagnosis and relevant clinical guidance.

9. Monitoring should consider both conditions. Clinicians should assess changes in ADHD symptoms, anxiety, sleep, physical health, medication tolerability and overall functioning. The timing of anxiety symptoms in relation to medication administration can help identify possible adverse effects.

10. Avoid treating symptoms without understanding their cause. Persistent anxiety does not automatically justify increasing ADHD medication or adding an anxiolytic treatment. Clinical decisions should follow a clear formulation of the patient's difficulties.

The central message of this lesson is that ADHD and anxiety should be assessed and managed as interacting conditions rather than competing diagnoses.

For prescribing clinicians, the goal is to identify the factors driving impairment, select appropriate interventions and monitor the overall response to treatment. With careful assessment and individualised management, many patients with coexisting ADHD and anxiety can achieve substantial improvements in both symptoms and everyday functioning.

6. Further Reading

The following resources provide further guidance on the assessment and management of ADHD and coexisting anxiety disorders. They have been selected to support clinical decision-making, particularly in relation to differential diagnosis, medication selection, treatment sequencing and monitoring.

6.1 NICE Guidelines

1. National Institute for Health and Care Excellence (NICE). Attention deficit hyperactivity disorder: diagnosis and management. NICE Guideline NG87. 2018, updated 2019.

https://www.nice.org.uk/guidance/ng87

This is the principal UK guideline for ADHD assessment and treatment.

Particularly relevant recommendations include:

• Assessing coexisting mental health conditions during ADHD assessment.

• Offering people with ADHD and anxiety disorders the same ADHD medication choices as other people with ADHD.

• Using slower titration and more frequent monitoring when coexisting mental health conditions are present.

• Monitoring medication effectiveness, adverse effects and functional outcomes.

2. NICE. Generalised anxiety disorder and panic disorder in adults: management. Clinical Guideline CG113. 2011, updated 2020.

https://www.nice.org.uk/guidance/cg113

Provides guidance on recognising and treating generalised anxiety disorder and panic disorder in adults, including psychological interventions, pharmacological treatment and stepped-care approaches.

3. NICE. Social anxiety disorder: recognition, assessment and treatment. Clinical Guideline CG159. 2013.

https://www.nice.org.uk/guidance/cg159

Particularly useful when distinguishing social anxiety from ADHD-related interpersonal difficulties, impulsivity and social communication problems.

It also provides age-specific recommendations for psychological and pharmacological treatment.

6.2 National and International Clinical Guidelines

4. Canadian ADHD Resource Alliance (CADDRA). Canadian ADHD Practice Guidelines. Fourth Edition and subsequent updates.

https://www.caddra.ca

These guidelines provide practical advice on ADHD assessment, medication management and psychiatric comorbidity.

They are particularly useful for understanding how coexisting anxiety influences treatment planning and prescribing decisions.

5. Australian ADHD Professionals Association (AADPA). Australian Evidence-Based Clinical Practice Guideline for ADHD. 2022.

https://adhdguideline.aadpa.com.au

An evidence-based guideline covering ADHD across the lifespan, including assessment, pharmacological treatment, psychological interventions and coexisting mental health conditions.

It provides a useful international comparison with NICE recommendations.

6. Wolraich ML, Hagan JF, Allan C, et al. Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents. Pediatrics. 2019;144(4).

https://doi.org/10.1542/peds.2019-2528

An American Academy of Pediatrics guideline emphasising comprehensive assessment, identification of comorbid conditions and coordinated treatment planning.

It is particularly relevant to clinicians working with children and adolescents.

6.3 Landmark Research Papers

7. Coughlin CG, Cohen SC, Mulqueen JM, Ferracioli-Oda E, Stuckelman ZD, Bloch MH. Meta-Analysis: Reduced Risk of Anxiety with Psychostimulant Treatment in Children with Attention-Deficit/Hyperactivity Disorder. Journal of Child and Adolescent Psychopharmacology. 2015;25(8):611–617.

https://doi.org/10.1089/cap.2015.0075

An important meta-analysis examining anxiety reported during psychostimulant treatment.

The findings challenge the assumption that stimulants generally worsen anxiety, demonstrating a lower reported risk of anxiety with psychostimulants compared with placebo across the included trials.

This paper is particularly relevant when discussing medication concerns with patients and families.

8. Geller D, Donnelly C, Lopez F, et al. Atomoxetine Treatment for Pediatric Patients with Attention-Deficit/Hyperactivity Disorder with Comorbid Anxiety Disorder. Journal of the American Academy of Child & Adolescent Psychiatry. 2007;46(9):1119–1127.

https://doi.org/10.1097/chi.0b013e3180ca8385

A randomised controlled trial examining atomoxetine in children and adolescents with ADHD and coexisting anxiety disorders.

The study provides evidence that atomoxetine can improve ADHD symptoms without necessarily worsening anxiety, with improvements in anxiety symptoms also observed.

It is useful when considering non-stimulant treatment options.

6.4 High-Quality Reviews and Consensus Statements

9. Katzman MA, Bilkey TS, Chokka PR, Fallu A, Klassen LJ. Adult ADHD and Comorbid Disorders: Clinical Implications of a Dimensional Approach. BMC Psychiatry. 2017;17:302.

https://doi.org/10.1186/s12888-017-1463-3

A clinically useful review exploring psychiatric comorbidity in adult ADHD.

It discusses the relationship between ADHD and anxiety, diagnostic overlap and the importance of individualised treatment planning.

10. Kooij JJS, Bijlenga D, Salerno L, et al. Updated European Consensus Statement on Diagnosis and Treatment of Adult ADHD. European Psychiatry. 2019;56:14–34.

https://doi.org/10.1016/j.eurpsy.2018.11.001

An international consensus statement addressing adult ADHD assessment, differential diagnosis, psychiatric comorbidity and treatment.

It provides a broader clinical framework for managing adults with ADHD and coexisting anxiety disorders.

6.5 Recommended Reading Priorities

For clinicians who wish to focus on the most immediately relevant resources, the following reading sequence is recommended:

1. NICE NG87 — essential UK prescribing guidance, including recommendations for patients with coexisting anxiety disorders.

2. Coughlin et al. (2015) — evidence challenging the assumption that stimulant medication routinely worsens anxiety.

3. Geller et al. (2007) — evidence concerning atomoxetine treatment in children and adolescents with ADHD and anxiety.

4. NICE CG113 and CG159 — practical guidance on identifying and treating independent anxiety disorders.

5. Katzman et al. (2017) — broader understanding of psychiatric comorbidity and clinical formulation.

Prescribers should use the current versions of relevant guidelines alongside the latest British National Formulary (BNF), BNF for Children and individual medication summaries of product characteristics when making prescribing decisions.

The overarching principle is that coexisting anxiety requires careful assessment and individualised treatment, but does not automatically exclude standard evidence-based ADHD medication.

7. Knowledge Check

The following ten multiple-choice questions are designed to consolidate the key learning points from this lesson. They focus on clinical assessment, differential diagnosis, prescribing decisions, medication monitoring and the management of coexisting ADHD and anxiety disorders.

Each question has one best answer. Detailed explanations are provided for both the correct and incorrect options to support clinical reasoning and reinforce safe prescribing practice.

Question 1: Understanding the Relationship Between ADHD and Anxiety

A 28-year-old man with recently diagnosed ADHD describes persistent anxiety about work. He frequently misses deadlines, forgets important tasks and struggles to organise his workload. He explains that most of his worries relate to the consequences of these difficulties.

Which of the following is the most appropriate interpretation?

A. The presence of anxiety indicates that the ADHD diagnosis is probably incorrect.

B. His anxiety is likely to represent a primary anxiety disorder that must be treated before ADHD.

C. His anxiety may be secondary to ADHD-related executive functioning difficulties.

D. Stimulant medication is contraindicated because he experiences anxiety.

E. Anxiety is a core diagnostic symptom of ADHD.

Correct Answer: C

Explanation

A. Incorrect. ADHD and anxiety frequently coexist. The presence of anxiety does not invalidate an ADHD diagnosis, particularly when there is evidence of longstanding neurodevelopmental symptoms.

B. Incorrect. Although a primary anxiety disorder should be considered, the clinical history suggests that much of his anxiety may arise from the consequences of executive functioning difficulties. A separate anxiety disorder should not be assumed without further assessment.

C. Correct. Difficulties with organisation, time management, task initiation and remembering responsibilities can create repeated stressful experiences. These may contribute to persistent anxiety about performance and potential consequences. Effective ADHD treatment may reduce anxiety by improving everyday functioning.

D. Incorrect. Anxiety alone is not a contraindication to stimulant medication. NICE recommends the same ADHD medication choices for patients with coexisting anxiety disorders as for other patients with ADHD.

E. Incorrect. Anxiety is not a core DSM-5 diagnostic criterion for ADHD. However, anxiety symptoms are common in people with ADHD and may arise through several interacting mechanisms.

Clinical learning point: Always explore what is driving a patient's anxiety before deciding whether it requires independent treatment.

Question 2: Differentiating ADHD From Anxiety

A 19-year-old university student describes difficulty concentrating during lectures. She explains that her attention is repeatedly interrupted by worries about failing examinations, disappointing her family and making mistakes. She did not experience significant attentional difficulties during childhood.

Which explanation is most consistent with the information provided?

A. ADHD is confirmed because she experiences poor concentration.

B. Anxiety-related cognitive interference may be contributing to her concentration difficulties.

C. ADHD and anxiety cannot occur together.

D. Her concentration difficulties are most likely caused by hyperactivity.

E. Stimulant medication should be started before further assessment.

Correct Answer: B

Explanation

A. Incorrect. Poor concentration is not specific to ADHD. A diagnosis requires a broader assessment of symptoms, developmental history, functional impairment and alternative explanations.

B. Correct. Anxiety can interfere with concentration when attention is repeatedly occupied by worry, anticipated threats or intrusive anxious thoughts. The absence of clear childhood ADHD symptoms makes an anxiety-related explanation particularly important to explore, although it does not independently exclude ADHD.

C. Incorrect. ADHD and anxiety disorders commonly coexist. Both may contribute to concentration difficulties in the same patient.

D. Incorrect. There is no evidence in the scenario of hyperactivity. Concentration difficulties can arise through several mechanisms, including anxiety, depression, sleep disturbance and ADHD.

E. Incorrect. ADHD medication should not be initiated solely because a patient reports poor concentration. A comprehensive assessment is required before making prescribing decisions.

Clinical learning point: The mechanism underlying poor concentration is often more diagnostically informative than the symptom itself.

Question 3: Choosing ADHD Medication in the Presence of Anxiety

A 13-year-old boy has been diagnosed with ADHD and generalised anxiety disorder. His ADHD symptoms cause substantial impairment at school and home. His parents are concerned that stimulant medication will worsen his anxiety.

According to NICE guideline NG87, which approach is most appropriate?

A. Avoid stimulant medication in all patients with anxiety disorders.

B. Prescribe atomoxetine as the mandatory first-line treatment because anxiety is present.

C. Treat the anxiety disorder completely before considering ADHD medication.

D. Offer the same ADHD medication choices as for other patients with ADHD, with appropriate individualisation and monitoring.

E. Prescribe an SSRI before starting any ADHD medication.

Correct Answer: D

Explanation

A. Incorrect. Anxiety is not an absolute contraindication to stimulant treatment. Some patients experience improvement in anxiety when ADHD symptoms become better controlled.

B. Incorrect. Atomoxetine may be appropriate in certain circumstances, but NICE does not recommend it as the mandatory first-line medication simply because anxiety is present.

C. Incorrect. There is no universal requirement to resolve anxiety before treating ADHD. Treatment sequencing should reflect symptom severity, functional impairment, risk and patient preference.

D. Correct. NICE recommends offering people with ADHD and an anxiety disorder the same medication choices as other people with ADHD. However, the presence of a coexisting mental health condition should inform the titration and monitoring plan.

E. Incorrect. An SSRI is not automatically required before ADHD treatment. The need for anxiety-specific pharmacological treatment depends on the diagnosis, severity, age and relevant clinical guidance.

Clinical learning point: Coexisting anxiety should influence prescribing decisions and monitoring, but should not automatically restrict access to effective ADHD medication.

Question 4: Anxiety Emerging During Stimulant Titration

A 16-year-old girl with ADHD has been taking modified-release methylphenidate with good effect. Following a dose increase, she develops increased nervousness, physical tension and difficulty sleeping. Her ADHD symptoms were already substantially improved at the previous dose.

What is the most appropriate next step?

A. Increase the methylphenidate dose further to improve emotional regulation.

B. Immediately add an SSRI without further assessment.

C. Review the temporal relationship with medication, assess other contributing factors and consider returning to the previously tolerated dose.

D. Permanently stop all ADHD medication because she has experienced anxiety.

E. Reassure her that anxiety cannot be caused by methylphenidate.

Correct Answer: C

Explanation

A. Incorrect. Increasing the dose may worsen adverse effects, particularly when the previous dose already provided substantial ADHD symptom control.

B. Incorrect. Adding an SSRI without clarifying the cause of the anxiety risks unnecessary polypharmacy. The symptoms may be related to the recent dose increase.

C. Correct. The temporal association between the dose increase and new symptoms suggests a possible medication-related adverse effect. The clinician should review medication timing, sleep, caffeine intake, environmental stressors and the additional benefit obtained from the higher dose. Returning to the previously tolerated dose may be appropriate.

D. Incorrect. Anxiety during titration does not necessarily mean that all ADHD medication is unsuitable. Dose reduction, formulation adjustment or alternative treatment may allow effective management.

E. Incorrect. Methylphenidate can cause nervousness, anxiety or sleep disturbance in some patients. These symptoms should be taken seriously and assessed appropriately.

Clinical learning point: The objective of titration is to identify the most effective and tolerable dose, not the highest possible dose.

Question 5: Treatment Sequencing in ADHD and Anxiety

A 32-year-old woman has confirmed ADHD and social anxiety disorder. Her ADHD symptoms cause significant difficulties with organisation and completing work. She also avoids social situations because of a persistent fear of negative evaluation.

Which treatment approach is most appropriate?

A. Treat ADHD alone because effective ADHD medication will always resolve social anxiety.

B. Treat social anxiety alone because ADHD medication cannot be used when anxiety is present.

C. Consider treatment for both conditions, guided by severity, functional impairment and patient preference.

D. Avoid psychological treatment because it is ineffective in patients with ADHD.

E. Prescribe two ADHD medications simultaneously to address both conditions.

Correct Answer: C

Explanation

A. Incorrect. Although ADHD treatment may reduce some anxiety-related difficulties, an independent social anxiety disorder may persist and require targeted intervention.

B. Incorrect. Coexisting anxiety does not automatically prevent ADHD medication treatment. Both conditions should be considered in the overall management plan.

C. Correct. Treatment should address the principal sources of impairment. ADHD medication may improve executive functioning, while CBT or other evidence-based interventions may be required for social anxiety. The timing and combination of interventions should be individualised.

D. Incorrect. Psychological interventions, particularly CBT, are established treatments for anxiety disorders. Practical adaptations may improve accessibility for patients with ADHD.

E. Incorrect. Combining ADHD medications is not an established treatment for social anxiety disorder. Medication choices should be based on clear indications and relevant prescribing guidance.

Clinical learning point: Coexisting ADHD and anxiety often require a coordinated treatment plan rather than an exclusive focus on one diagnosis.

Question 6: Atomoxetine and Coexisting Anxiety

A 25-year-old man with ADHD and generalised anxiety disorder asks whether atomoxetine would be a better choice than methylphenidate because he experiences anxiety.

Which statement is most accurate?

A. Atomoxetine is licensed in the UK specifically to treat generalised anxiety disorder.

B. Atomoxetine is always superior to stimulant medication when ADHD and anxiety coexist.

C. Atomoxetine is contraindicated in patients with anxiety disorders.

D. Atomoxetine may be appropriate for ADHD with coexisting anxiety, but medication selection should remain individualised.

E. Atomoxetine does not require monitoring of cardiovascular observations.

Correct Answer: D

Explanation

A. Incorrect. Atomoxetine is licensed for ADHD, not as a primary treatment for generalised anxiety disorder.

B. Incorrect. There is insufficient evidence to conclude that atomoxetine is universally superior to stimulants in patients with coexisting anxiety. Stimulants remain appropriate for many patients.

C. Incorrect. Anxiety disorders are not a general contraindication to atomoxetine. Research suggests that atomoxetine can improve ADHD symptoms without necessarily worsening coexisting anxiety.

D. Correct. Atomoxetine may be useful when stimulants are ineffective, poorly tolerated or otherwise unsuitable. However, the presence of anxiety alone should not determine medication selection. Previous response, adverse effects, patient preference and clinical circumstances remain important.

E. Incorrect. Atomoxetine can increase heart rate and blood pressure. Appropriate baseline assessment and ongoing monitoring are required.

Clinical learning point: Non-stimulant medication should not automatically be regarded as safer or more effective for anxiety simply because it is not a stimulant.

Question 7: Persistent Anxiety Despite Effective ADHD Treatment

A 21-year-old university student has achieved good control of ADHD symptoms with lisdexamfetamine. Her concentration, organisation and academic performance have improved substantially.

However, she continues to experience excessive worry about several areas of life, difficulty controlling her worries, muscle tension and sleep disturbance.

What is the most appropriate next step?

A. Increase lisdexamfetamine because persistent anxiety indicates inadequate ADHD treatment.

B. Assess for an independent anxiety disorder and consider appropriate psychological or pharmacological treatment.

C. Stop lisdexamfetamine because anxiety is always caused by stimulant medication.

D. Reassure her that anxiety is a normal part of ADHD and requires no further assessment.

E. Prescribe a benzodiazepine for indefinite daily use.

Correct Answer: B

Explanation

A. Incorrect. Her ADHD symptoms are already well controlled. Increasing the stimulant may provide little additional benefit and could increase adverse effects.

B. Correct. Persistent excessive worry across multiple areas of life, associated with physical symptoms and functional impairment, may indicate generalised anxiety disorder. A structured assessment is appropriate, followed by evidence-based treatment where indicated.

C. Incorrect. Anxiety may be independent of stimulant treatment. The clinician should assess its history, timing and relationship to medication before attributing causation.

D. Incorrect. Although anxiety is common in ADHD, clinically significant anxiety should not be dismissed as an inevitable consequence of the condition.

E. Incorrect. Benzodiazepines are not recommended for routine long-term management of generalised anxiety disorder because of concerns including dependence, sedation and cognitive impairment. NICE restricts their use in GAD to short-term measures during crises.

Clinical learning point: When ADHD symptoms are adequately controlled but anxiety persists, reconsider the formulation rather than automatically escalating ADHD medication.

Question 8: Drug Interactions in Combined Treatment

A 29-year-old woman is taking atomoxetine for ADHD. She is subsequently prescribed fluoxetine for a coexisting psychiatric condition.

Which interaction is most clinically relevant?

A. Fluoxetine significantly inhibits CYP2D6 and may increase atomoxetine exposure.

B. Fluoxetine reduces atomoxetine concentrations by accelerating its metabolism.

C. Atomoxetine prevents fluoxetine from having any therapeutic effect.

D. The combination is always contraindicated.

E. No interaction assessment is required because atomoxetine is a non-stimulant.

Correct Answer: A

Explanation

A. Correct. Atomoxetine is primarily metabolised through CYP2D6. Fluoxetine is a strong CYP2D6 inhibitor and can substantially increase atomoxetine exposure. This may increase the likelihood of adverse effects and requires consideration of dose adjustment and monitoring in accordance with the product information.

B. Incorrect. Fluoxetine inhibits rather than accelerates CYP2D6-mediated atomoxetine metabolism.

C. Incorrect. Atomoxetine does not prevent fluoxetine from exerting its therapeutic effects.

D. Incorrect. The combination is not universally contraindicated, but it requires careful prescribing and monitoring.

E. Incorrect. Non-stimulant medications can have clinically important pharmacokinetic and pharmacodynamic interactions. The absence of stimulant activity does not eliminate interaction risks.

Clinical learning point: When combining ADHD medication with treatment for anxiety or depression, always review the specific medicines, metabolic pathways and interaction risks.

Question 9: Anxiety and Behavioural Difficulties in Children

An 11-year-old boy with ADHD has become increasingly distressed before school. He frequently complains of abdominal pain, becomes irritable when asked to get ready and sometimes refuses to leave home.

His parents believe that his ADHD medication dose needs increasing because his behaviour has deteriorated.

What is the most appropriate clinical approach?

A. Increase the ADHD medication immediately because school refusal indicates uncontrolled impulsivity.

B. Assume the abdominal pain is a medication adverse effect and stop treatment permanently.

C. Explain that school refusal is always caused by separation anxiety.

D. Assess the underlying causes of distress, including anxiety, school experiences, physical symptoms and ADHD-related difficulties, before changing medication.

E. Advise the parents to ignore the behaviour because it is attention-seeking.

Correct Answer: D

Explanation

A. Incorrect. School refusal and distress do not necessarily indicate inadequate ADHD symptom control. Increasing medication without understanding the underlying difficulty may be ineffective or harmful.

B. Incorrect. Abdominal pain may be associated with medication, anxiety or a physical health condition. Its cause should be assessed rather than assumed.

C. Incorrect. Separation anxiety is one possible explanation, but school-related distress can arise from social anxiety, bullying, learning difficulties, sensory distress and other factors.

D. Correct. The clinician should explore the child's emotional experience, school environment, physical symptoms, family circumstances and medication response. The aim is to understand what is driving the behaviour before deciding on treatment.

E. Incorrect. Dismissing distress as attention-seeking risks overlooking significant anxiety, environmental difficulties or other clinical concerns.

Clinical learning point: Behaviour is not a diagnosis. Understanding the factors underlying behavioural change is essential before altering ADHD treatment.

Question 10: Clinical Monitoring and Safety

A 17-year-old boy receiving methylphenidate develops episodes of palpitations and chest discomfort following a recent dose increase. He has a history of anxiety and believes the symptoms are probably panic attacks.

What is the most appropriate response?

A. Reassure him that chest discomfort is harmless because he has an anxiety disorder.

B. Increase methylphenidate to improve emotional regulation.

C. Advise him to continue the medication unchanged until his next routine review.

D. Prescribe an SSRI without investigating the physical symptoms.

E. Arrange prompt medical assessment, withhold stimulant medication pending appropriate evaluation, and determine whether urgent assessment is required.

Correct Answer: E

Explanation

A. Incorrect. Although anxiety and panic attacks can produce palpitations and chest discomfort, potentially significant cardiovascular symptoms should not automatically be attributed to anxiety.

B. Incorrect. Increasing stimulant medication in the presence of concerning cardiovascular symptoms may increase risk and is not appropriate without assessment.

C. Incorrect. New palpitations and chest discomfort following a dose increase require timely evaluation rather than routine observation alone.

D. Incorrect. Prescribing an SSRI does not address the need to investigate potentially significant cardiovascular symptoms.

E. Correct. New chest discomfort and palpitations following stimulant dose escalation require medical assessment. The urgency depends on the symptoms and associated features, including persistent chest pain, syncope, breathlessness or haemodynamic compromise. Emergency assessment is indicated when acute serious cardiovascular pathology is suspected. Stimulant medication should be withheld while a potentially serious medication-related cardiovascular problem is evaluated, and restarting should depend on the findings and appropriate clinical clearance.

Clinical learning point: Never assume that new physical symptoms are caused by anxiety simply because the patient has an established anxiety disorder.

Consolidating Your Learning

These questions reinforce five essential principles for clinical practice.

First, establish the relationship between ADHD and anxiety. Anxiety may be secondary to ADHD-related difficulties, represent an independent disorder or arise through several interacting mechanisms.

Second, do not automatically avoid stimulant medication. NICE recommends the same ADHD medication choices for patients with coexisting anxiety disorders, while recognising the need for individualised titration and monitoring.

Third, treat clinically significant comorbidity appropriately. Effective ADHD treatment may improve some anxiety symptoms, but independent anxiety disorders may require psychological or pharmacological treatment.

Fourth, interpret changes during medication treatment carefully. The timing of symptoms, dose changes, sleep, environmental factors and functional outcomes can help distinguish medication adverse effects from underlying anxiety.

Finally, prioritise patient safety and overall functioning. The aim of prescribing is not simply to reduce individual symptom scores, but to achieve meaningful improvement in everyday life while minimising adverse effects and recognising situations requiring further assessment.

A clinician who can apply these principles will be better equipped to manage the complexities of ADHD and anxiety safely, confidently and effectively.