What are the most common psychiatric disorders seen in child and adolescent psychiatric evaluations?

Most Common Psychiatric Disorders in Child and Adolescent Psychiatric Evaluations

The most frequently encountered psychiatric disorders in child and adolescent psychiatric evaluations are attention-deficit/hyperactivity disorder (ADHD), anxiety disorders, oppositional defiant disorder (ODD), and depressive disorders, with ADHD being the single most prevalent condition at approximately 8.6% prevalence. 1

Primary Disorders by Prevalence

ADHD (Most Common)

• ADHD represents the most common psychiatric disorder in pediatric evaluations, with a 12-month prevalence of 8.6% 1
• Boys have 2.1 times greater prevalence than girls 1
• ADHD is particularly prominent in children with intellectual disability, where rates are substantially elevated compared to typically developing children 2

Anxiety Disorders (Second Most Common)

• Anxiety disorders collectively represent the most common psychiatric illness category affecting children and adolescents 3
• 12-month prevalence for panic disorder or generalized anxiety disorder is 0.7%, though this underestimates total anxiety disorder prevalence as it excludes separation anxiety, social anxiety, and specific phobias 1
• Anxiety disorders show particularly high rates in children with intellectual disability 2
• No significant gender differences in overall anxiety disorder rates 1

Mood Disorders (Third Most Common)

• 12-month prevalence of mood disorders is 3.7% 1
• Girls have twofold higher rates than boys 1
• Depression is a common presenting concern, though adolescent depression often occurs with comorbid oppositional defiant disorder, anxiety, and substance disorders 4

Disruptive Behavior Disorders

• Oppositional defiant disorder (ODD) shows particularly high rates in psychiatric evaluations, especially among children with intellectual disability 2
• Conduct disorder has a 12-month prevalence of 2.1% 1
• No gender differences in conduct disorder rates 1
• ODD is notable for predicting a wide range of young adult disorders, including anxiety and depression 4

Critical Diagnostic Considerations

Comorbidity Patterns

• High comorbidity is the rule rather than the exception in child and adolescent psychiatry 5
• Depression commonly co-occurs with oppositional defiant disorder, anxiety, and substance disorders 4
• ADHD frequently presents with comorbid anxiety and disruptive behavior disorders 2

Age-Related Presentation Patterns

• Anxiety disorder treatment rates are higher in children (64%) than adolescents (20%), while depressive disorder treatment rates are higher in adolescents (36%) than children (11%) 6
• Hyperactivity symptoms are more prominent earlier in development, while inattentive symptoms persist longer 2

Special Populations

• Children with intellectual disability experience psychiatric disorders at least three times more often than typically developing children 2
• Autism spectrum disorder commonly co-occurs with intellectual disability 2
• Serious behavioral problems occur 2.5 to 4 times more frequently in children with intellectual disability 2

Less Common but Critical Diagnoses

Psychotic Disorders

• Approximately 50% of adolescents with bipolar disorder may be initially misdiagnosed as schizophrenia 7
• Bipolar disorder with psychotic features frequently presents with florid psychosis including hallucinations, delusions, and thought disorder in teenagers 7
• Medical causes account for approximately 20% of acute psychosis cases and must be systematically excluded 8, 7

Eating Disorders

• 12-month prevalence is 0.1%, representing the least common category in general psychiatric evaluations 1

Common Diagnostic Pitfalls to Avoid

• Do not assume anxiety or depression is the primary diagnosis without assessing for ADHD and ODD, as these frequently underlie or co-occur with mood and anxiety symptoms 2, 4
• Avoid "diagnostic overshadowing" where behavioral symptoms are attributed to intellectual disability rather than recognizing comorbid psychiatric disorders 2
• Only approximately one-half of children with diagnosed psychiatric disorders have sought treatment with a mental health professional, indicating substantial unmet need 1
• African-American youth are more likely to be misdiagnosed with psychotic conditions and less likely to receive mood disorder diagnoses due to clinician bias 8

Risk Factors Requiring Assessment

• Family psychiatric history, particularly for bipolar disorder, psychotic disorders, and substance abuse 2, 8
• Severity of cognitive, adaptive, and language impairments 2
• Trauma exposure and abuse history (children with intellectual disability have 11.3% rate of substantiated maltreatment) 2
• Low family socioeconomic status and single biological parent as caregiver 2
• Stressful life events including moves, family problems, and school transitions 2