Executive function, memory, and learning in Tourette's syndrome.

Young people with Tourette's syndrome (TS) alone, TS plus attention-deficit/hyperactivity disorder (+ADHD), or TS plus obsessive-compulsive disorder (+OCD) were compared with a healthy control group on a set of measures of executive functioning, memory, and learning. The TS-alone group was impaired on one executive measure involving inhibition and strategy generation but did not differ significantly from the healthy control group on other measures. The TS+ADHD group showed impairment on several executive measures. There was no evidence of impairment in implicit aspects of memory and learning for any of the TS groups. The findings are discussed in terms of the frontostriatal hypothesis of TS and the contribution of comorbid symptomatology.