Objective: This study evaluated the effects on behavior and sleep of methylphenidate (MPH) administered at 4 PM to children with attention-deficit hyperactivity disorder (ADHD).
Methodology: Twelve children admitted to a child psychiatric inpatient service with ADHD participated in a double-blind, crossover study in which they received a 4 PM dose of either 15 mg of MPH, 10 mg of MPH, or a placebo in random order for 12 consecutive days. Ratings of behavior, including ADHD symptoms, pertaining to the period from dose administration until sleep onset, were supplied nightly by hospital staff. Sleep latency and sleep adequacy were also assessed for each night.
Results: MPH resulted in markedly improved behavioral control compared with placebo; there was no difference between 15-mg and 10-mg MPH doses. MPH did not alter sleep latencies observed with the placebo. Children were more often rated as less tired on awakening after nights that they received 10 mg of MPH compared with 15 mg of MPH and the placebo. Weight loss was apparent among 83% of the patients, but dinner intake did not vary with third-dose condition.
Conclusions: Morning and noon administration of stimulants to children with ADHD is a near-universal practice, but many clinicians avoid a third, late-afternoon administration for fear of inducing insomnia. This study's findings show that children with ADHD derive substantial symptom reduction from MPH administered in late afternoon, with no untoward effects on sleep. Therefore, three-times-a-day dosing should be considered for those children exhibiting ADHD symptoms in the evening. Adverse effects on sleep latency were not apparent in the sample overall. Nonetheless, monitoring for possible aggravation of sleep problems and weight loss remains sound treatment practice.