Conditions: Tourettes Syndrome Tic
Keywords: Tic disorders, Tourette syndrome Chronic Tic Disorders
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 31
Healthy volunteers: no

Brief summary:
Tourette syndrome is a childhood-onset neuropsychiatric disorder characterized by multiple motor and vocal tics that last for at least a year in duration. Currently, there exist several effective pharmacological treatments for childhood tics including alpha-2 agonist medications (guanfacine and clonidine) and neuroleptics (antipsychotic) medications. These medications, however, have significant side-effects and are only partially efficacy in treating tics.

N-acetylcysteine (NAC) is a natural supplement that acts as an antioxidant and glutamate modulating agent. NAC has been used safely for decades in doses 20-40 times higher than in this trial as an antidote for acetaminophen overdose. The only side-effect commonly seen with NAC is nausea and this side-effect is seldom seen in the doses used in this trial.

NAC has recently been demonstrated to be effective in a double-blind, placebo-controlled trial in adults with trichotillomania (chronic hair pulling). Hairpulling is hypothesized to be closely related to tics because these conditions (1) have similar clinical characteristics -- both groups typically experience urges before engaging in pulling or tics, (2) neuroimaging studies suggest they involve similar brain circuits -- the basal ganglia, (3) the same pharmacological treatments (neuroleptics) may be effective for both conditions and (4) they tend to be inherited together in families. In other trials NAC has evidence of some efficacy in treating diverse psychiatric conditions such as bipolar depression, schizophrenia and cocaine dependence.

The investigators are conducting this trial to determine if NAC is an effective treatment for tics.

Detailed description:

Arms:
arm 1: NAC was titrated up to a maximum dose of 2400 mg over the course of 2 weeks. Subjects were assigned 600 mg twice a day for weeks 1-2, and then were assigned 1200 mg twice a day for the remainder of the 12 week study. arm 2: Placebo: Subjects were assigned to take two capsules twice a day for weeks 1-2, and then were assigned 4 capsules twice a day for the remainder of the 12 week study.

Interventions: intervention 1: N-Acetylcysteine (NAC) intervention 2: Placebo
Intervention descriptions: intervention 1: 1 600mg capsule twice a day for 2 weeks and then 2 600mg capsules twice a day for the remaining 10 weeks of the trial. intervention 2: 1 600mg Capsule twice a day for two weeks then 2 600mg capsules twice a day for the remaining 10 weeks of the study. Children receiving placebo will be offered the active intervention after the double-blind portion of the trial.

Protocol document: