What is the relationship between Attention Deficit Hyperactivity Disorder (ADHD) and comorbid anxiety and mood disorders?

The Relationship Between ADHD and Anxiety/Mood Disorders

ADHD frequently co-occurs with anxiety and mood disorders, with comorbidity rates of approximately 25% for anxiety disorders and varying rates for mood disorders, significantly impacting clinical presentation, treatment approach, and long-term outcomes. 1

Prevalence and Comorbidity Patterns

• ADHD is commonly comorbid with other psychiatric disorders, with anxiety disorders being among the most frequent comorbidities, affecting approximately 25% of individuals with ADHD 1
• In children with ADHD, population-based studies show approximately 14% have comorbid anxiety disorders and 9% have comorbid depressive disorders 2
• The comorbidity between ADHD and these disorders tends to increase with age, with more anxiety and mood disorders appearing as children grow older 2
• These comorbidities significantly increase family and social dysfunction compared to those with ADHD alone 2

Impact on Clinical Presentation and Functioning

• The presence of comorbid anxiety or mood disorders substantially changes the presentation, prognosis, and treatment approach for ADHD 1
• In childhood, generalized anxiety disorder may partially inhibit the typical inhibitory dysfunction seen in ADHD 1, 3
• In adolescence, comorbid anxiety may worsen working memory deficits 1, 3
• In adulthood, comorbid anxiety often enhances sleep problems 1
• Children with both ADHD and anxiety/mood disorders show greater impairment in social functioning and academic achievement 2
• Comorbid ADHD and anxiety may present with qualitatively different anxiety symptoms compared to anxiety disorders alone 3

Neurobiological Considerations

• ADHD and anxiety disorders share some common neurobiological dysfunctions but also have distinct neurobiological abnormalities, suggesting they are separate but related conditions 1
• Sluggish cognitive tempo measures in ADHD show strong correlations with anxiety measures, particularly in the inattentive presentation 3
• The relationship between these disorders may be bidirectional - ADHD symptoms can exacerbate anxiety and depression, while anxiety and depression can worsen attentional difficulties 2

Treatment Implications

Medication Considerations

• When ADHD co-occurs with anxiety disorders, stimulant medications remain effective for ADHD symptoms but may not adequately address anxiety symptoms 2, 4
• Atomoxetine has been specifically studied in ADHD patients with comorbid anxiety disorders and does not worsen anxiety symptoms, as demonstrated in controlled trials 5
• In a 12-week double-blind trial with children and adolescents with ADHD and anxiety disorders (separation anxiety, generalized anxiety, or social phobia), atomoxetine did not worsen anxiety as measured by the Pediatric Anxiety Rating Scale 5
• Similarly, in adults with ADHD and social anxiety disorder, atomoxetine did not worsen anxiety symptoms 5
• For patients with significant mood symptoms, careful consideration of medication effects is needed, as some ADHD medications may affect emotional lability 6
• Methylphenidate may reduce the risk of irritability, anxiety, and euphoria but can worsen apathy and reduce talkativeness 6
• Amphetamines may worsen emotional lability in some patients 6

Treatment Sequencing

• For comorbid ADHD and major depressive disorder (MDD), if MDD is the primary disorder or has severe symptoms (psychosis, suicidality, severe neurovegetative signs), depression should be treated first 2
• If depression is less severe or secondary to ADHD, starting with stimulant treatment for ADHD may be beneficial as it can quickly reduce ADHD symptoms and potentially improve depressive symptoms 2
• For comorbid anxiety disorders, evidence suggests that treating the anxiety disorder until clear symptom reduction is observed before treating ADHD may be more effective than treating ADHD first 7
• Alternatively, a combined treatment approach addressing both conditions simultaneously may be appropriate 7

Psychosocial Interventions

• Individuals with comorbid ADHD and anxiety disorders often benefit from adjunctive psychosocial interventions in addition to medication 1
• Patients with ADHD and anxiety may show greater benefit from psychosocial interventions than those with ADHD alone 4
• Cognitive-behavioral therapy alone may be insufficient for these patients, often requiring additional pharmacological treatment 1

Clinical Assessment and Monitoring

• The American Academy of Pediatrics recommends screening for comorbid conditions, including anxiety and mood disorders, in all patients evaluated for ADHD 2
• This is particularly important for adolescents, who should be assessed for symptoms of substance use, anxiety, depression, and learning disabilities 2
• Clinicians should be aware that oppositional behavior in children with ADHD may sometimes be used to manage anxiety in the face of overwhelming demands 2
• ADHD should be managed as a chronic condition requiring ongoing monitoring for the emergence of comorbid conditions throughout the lifespan 2

Special Considerations

• Younger patients and females may be at higher risk for emotional side effects from ADHD medications, particularly with high-dose, immediate-release stimulants 6
• The relationship between ADHD and mood disorders is complex, with some debate about the prevalence of bipolar disorder among children with ADHD 4
• A subgroup of emotionally labile children with ADHD presents particular management challenges and may require mood stabilizers or atypical antipsychotics in addition to ADHD treatment 4
• When treating comorbid conditions, coordination between behavioral health providers is essential to ensure comprehensive care 8