The safety and efficacy of immediate-release methylphenidate (MPH-IR) for the treatment of attention deficit hyperactivity disorder (ADHD) in children (ages 6-12 years) with Tourette's syndrome (96%) or chronic motor tic disorder (4%) were evaluated at State University of New York, Stony Brook. Seventy one children, in 2 cohorts, were treated with three doses of MPH (0.1, 0.3, and 0.5 mg/kg) and placebo twice daily for 2 weeks each, double-blind, and effects were assessed with a battery of parent, teacher, child, and physician-completed rating scales and laboratory tasks. MPH-IR effectively suppressed ADHD, oppositional defiant disorder, and peer aggression behaviors, without altering the overall severity of tic disorder or obsessive compulsive disorder. Dose-response was variable. Teacher ratings indicated that MPH-IR treatment decreased the frequency and severity of the tic disorder. The physician's 2-minute Tic/Habit Count showed an increase in simple but not complex motor movements (0.3 and 0.5 mg/kg > placebo). For the Simulated Classroom, the tic frequency was slightly higher for the 0.5 mg/kg dose. Adverse effects related to dose included heart rate and blood pressure increases and weight loss. MPH-IR is not contraindicated as a short-term therapy for children with ADHD and chronic tic disorder, but treatment should be carefully monitored to exclude possible tic exacerbation in susceptible individuals. [1]

COMMENT. These authors recommend a carefully monitored trial of immediate-release methylphenidate (MPH) in the treatment of ADHD with comorbid chronic tic disorder (CTD). Larger doses of MPH resulted in minimal increased effectiveness, but with a greater likelihood of tic exacerbation and adverse effects on heart rate, blood pressure and weight. The improved tic control reported by teachers in the classroom, in contrast to the physicians' report of an increase in simple tics with larger doses, may be explained by a student's ability to suppress tics in the stigmatizing school environment. Evaluations in multiple environments are necessary to determine the true frequency and severity of a tic disorder. A non-stimulant such as atamoxetine may be an alternative initial drug of choice for the treatment of ADHD and comorbid CTD, but immediate-release MPH in conservative doses may be safe and effective.