ADHD subtypes and comorbid anxiety, depression, and oppositional-defiant disorder: differences in sleep problems.

OBJECTIVE Sleep problems were analyzed in children with ADHD (Attention-deficit hyperactivity disorder). METHODS Scales were completed by parents of 135 control children and 681 children with ADHD combined type (ADHD-C) or inattentive type (ADHD-I) with or without comorbid oppositional defiant disorder (ODD), anxiety, or depression. RESULTS Children with ADHD-I alone had the fewest sleep problems and did not differ from controls. Children with ADHD-C had more sleep problems than controls and children with ADHD-I. Comorbid anxiety/depression increased sleep problems, whereas ODD did not. Daytime sleepiness was greatest in ADHD-I and was associated with sleeping more (not less) than normal. Medicated children had greater difficulty falling asleep than unmedicated children. CONCLUSIONS Differences in sleep problems were found as a function of ADHD subtype, comorbidity, and medication.