Sleep problems in children with attention-deficit/hyperactivity disorder: impact of subtype, comorbidity, and stimulant medication.

OBJECTIVE

To determine the relationship of sleep problems to attention-deficit/hyperactivity disorder (ADHD), diagnostic subtype, comorbid disorders, and the effects of stimulant treatment.

METHOD

On the basis of clinical diagnostic interviews, children aged 6 to 12 years were assigned to 4 groups: unmedicated ADHD (n = 79), medicated ADHD (n = 22), clinical comparison (n = 35), and healthy nonclinical comparison (n = 36). These groups were compared on 2 sleep questionnaires completed by the parents that assessed current sleep problems and factors associated with sleep difficulties (i.e., sleep routines, sleep practices, child and family sleep history).

RESULTS

Factor analysis revealed 3 sleep problem categories: dyssomnias, parasomnias, and sleep-related involuntary movements. Linear regression analyses showed that (1) dyssomnias were related to confounding factors (i.e., comorbid oppositional defiant disorder and stimulant medication) rather than ADHD; (2) parasomnias were similar in clinical and nonclinical children; and (3) the DSM-IV combined subtype of ADHD was associated with sleep-related involuntary movements. However, sleep-related involuntary movements were more highly associated with separation anxiety.

CONCLUSIONS

The results suggest that the relationship between sleep problems and ADHD is complex and depends on the type of sleep problem assessed as well as confounding factors such as comorbid clinical disorders and treatment with stimulant medication.