DISENTANGLING THE OVERLAP BETWEEN TOURETTES DISORDER AND ADHD

Objective: To identify similarities and differences in neuropsychiatri c correlates in children with Tourette's syndrome (TS) and those with ADHD. Method: The sample consisted of children with Tourette's syndrom e with ADHD (N = 79), children with Tourette's syndrome without ADHD ( N = 18), children with ADHD (N = 563), psychiatrically referred childr en (N = 212), and healthy controls (N = 140). Results: Disorders speci fically associated with Tourette's syndrome were obsessive compulsive disorder (OCD) and simple phobias. Rates of other disorders, including other disruptive behavioral, mood, and anxiety disorders, neuropsycho logic correlates, and social and school functioning were indistinguish able in children with Tourette's and ADHD. However, children with Tour ette's syndrome plus ADHD had more additional comorbid disorders overa ll and lower psychosocial function than children with ADHD. Conclusion s: These findings confirm previously noted associations between Touret te's syndrome and OCD but suggest that disruptive behavioral, mood, an d anxiety disorders as well as cognitive dysfunctions may be accounted for by comorbidity with ADHD. However, Tourette's syndrome plus ADHD appears to be a more severe condition than ADHD alone.