Recurrent episodes of explosive anger occur in some children with Tourette Syndrome (TS) that often require psychiatric evaluation and intervention. These outbursts, which are quite atypical for the child’s usual character, may occur quite suddenly in response to seemingly trivial frustrations. The outbursts are grossly out of proportion to any obvious provocation or stress. These symptoms are poorly understood, cause considerable anguish for both patients and families, and pose serious challenges for effective treatment. Currently, treatment of such episodes is often nonspecific. For many, treatment entails lengthy trials of a variety of medications, or the use of different psychotherapies with unpredictable and inconsistent results. However, once we have a better understanding of both the neurobiological and psychological basis for this difficult and complex manifestation, more specific and thus improved treatment approaches may be devised. Our previous clinical study in this area demonstrated that these outbursts are unlikely to occur with people who have TS alone, but rather the episodes become more common when TS is accompanied by additional disorders (comorbidities) such as Attention Deficit Hyperactivity Disorder (ADHD), Obsessive Compulsive Disorder (OCD), and others. Our experience suggests that many of the individuals who have these symptoms demonstrate behaviors that are at the same time impulsive and rigid. For this reason, we intend to test the hypothesis that combined symptomatic ADHD and OCD comorbidities are a significant risk factor for having explosive outbursts in TS. This current clinical study will attempt to find out which comorbidities, alone and in combination, may place the child with TS at greatest risk for experiencing explosive outbursts. In this investigation, we will evaluate additional current and lifetime diagnoses not examined in our prior study, and also we will examine whether other factors such as current medications, medication side effects, sensory sensitivities, and family environment may be clinical predictors of explosive outbursts in Tourette Syndrome. Cathy L. Budman, M.D. NYU/North Shore University Hospital, Manhasset, NY Award $38,900 Tourette Association of America Inc. – Research Grant Award 1999-2000