Effects of methylphenidate on sleep in children with attention-deficient hyperactivity disorder. An activity monitor study.

Objective: To assess the effects of methylphenidate hydrochloride on sleep patterns in children diagnosed as having attention-deficit hyperactivity disorder (ADHD).

Design: A double-blind, controlled drug-placebo cross-over design.

Setting: Home.

Subjects: Ten children (aged 6 years 9 months to 12 years & months) diagnosed as having ADHD were consecutively recruited and compared with age- and sex-matched normal controls.

Treatment: Methylphenidate hydrochloride (0.3 to 0.4 mg/kg) or placebo was administered at 7:30 AM.

Measurements and results: Each child underwent activity monitoring at home during 6 days of no treatment (baseline) followed by placebo and methylphenidate treatment. The results of the three trial stages, as well as those of the 20 age- and sex-matched normal controls, were compared. A shorter total sleep duration was evident during the methylphenidate treatment compared with that of baseline and placebo treatment. The amount of quiet sleep was lower (however, not significantly) among the study group compared with controls, whereas no such difference was noted during methylphenidate treatment. Night-to-night sleep pattern stability was found. No other differences were found either between children with ADHD and controls or between on and off stages of methylphenidate treatment.

Conclusions: These results support the notion that ADHD is a centrally generated disorder attributable to hypoarousal, which subsequently stimulates motor overactivity. Methylphenidate does not appear to affect sleep patterns adversely and possibly normalizes them in patients with ADHD.