Stimulant medication withdrawal during long-term therapy in children with comorbid attention-deficit hyperactivity disorder and chronic multiple tic disorder

Objectives. In this study we examined changes in attention-deficit hyperact ivity disorder behaviors and motor and vocal ties during withdrawal from lo ng-term maintenance therapy with stimulant medication. Methods. Subjects were 19 children with attention-deficit hyperactivity dis order and chronic tic disorder who had received methylphenidate (n = 17) or dextroamphetamine (n = 2) for a minimum of 1 year. Children were switched to placebo under double-blind conditions. Treatment effects were assessed b y using direct observations of child behavior in a simulated (clinic-based) classroom and behavior rating scales completed by parents and clinician. Results. There was no change (group data) in the frequency or severity of m otor ties or vocal lies during the placebo condition compared with maintena nce dose of stimulant medication (ie, no evidence of tic exacerbation while receiving medication or of a withdrawal reaction), There was no evidence o f tic exacerbation in the evening as a rebound effect. Treatment with the m aintenance dose was also associated with behavioral improvement in attentio n-deficit hyperactivity disorder behaviors, indicating continued efficacy. Conclusions. Abrupt withdrawal of stimulant medication in children receivin g long-term maintenance therapy does not appear to result in worsening of t ic frequency or severity. Nevertheless, these findings do not preclude the possibility of drug withdrawal reactions in susceptible individuals.