Several small trials with clonidine have been carried out in children with Tourette's syndrome, including placebo-controlled trials and head-to-head comparisons with another active drug. In a 12-week randomized trial of clonidine versus placebo in 47 subjects (ages 7–48 years old) with Tourette's syndrome, Leckman et al. (1991) showed that clonidine was more effective than placebo in controlling tics. When compared directly with the antipsychotic medication risperidone (n=9), clonidine (n=12) showed a similar reduction in overall tic severity and ADHD symptoms (Gaffney et al. 2002). The results of these studies suggest that at dosages ranging from 0.15 to 0.3 mg/day, clonidine exerts a moderate benefit on tics.