The findings from case reports and patient questionnaire surveys have been interpreted as indicating that administration of stimulants is ill-advised for the treatment of attention-deficit hyperactivity disorder in children with tic disorder.
Thirty-four prepubertal children with attention-deficit hyperactivity disorder and tic disorder received placebo and three dosages of methylphenidate hydrochloride (0.1, 0.3, and 0.5 mg/kg) twice daily for 2 weeks each, under double-blind conditions. Treatment effects were assessed using direct observations of child behavior in a simulated (clinic-based) classroom and using rating scales completed by the parents, teachers, and physician.
Methylphenidate effectively suppressed hyperactive, disruptive, and aggressive behavior. There was no evidence that methylphenidate altered the severity of tic disorder, but it may have a weak effect on the frequency of motor (increase) and vocal (decrease) tics.
Methylphenidate appears to be a safe and effective treatment for attention-deficit hyperactivity disorder in the majority of children with comorbid tic disorder.