Comorbidity of obsessive-compulsive disorder and attention-deficit/ hyperactivity disorder in referred children and adolescents

Objective: The aim of this study was to explore whether comorbid attention-deficit/hyperactivity disorder (ADHD) affects the clinical expression and outcome of obsessive-compulsive disorder (OCD) in a clinical sample. Method: A consecutive series of 94 children and adolescents (mean age, 13.6 ± 2.8 years) with current diagnosis of OCD were included in the study. Twenty-four (25.5%) patients were diagnosed as having a comorbid ADHD. Subjects with OCD plus ADHD were compared with subjects with OCD but without ADHD. Results: Comorbid ADHD with OCD was significantly associated with a higher rate of males, an earlier onset of OCD, a greater psychosocial impairment, and a heavier comorbidity, namely, with bipolar disorder, tic disorder, and oppositional defiant disorder/conduct disorder. Phenomenology of obsessions and compulsions and outcome were not affected by ADHD comorbidity. Conclusions: A screening for ADHD should be performed in patients with OCD, as these patients and their parents are frequently not aware that the impairment may be partly due to a comorbid ADHD.