Validation of the presence of comorbidities in a Danish clinical cohort of children with Tourette syndrome.

Tourette syndrome (TS) is characterized by the presence of motor and vocal tics and is often accompanied by comorbid symptoms. We assessed the frequency of the comorbid symptoms obsessive-compulsive disorder obsessive-compulsive disorder, attention-deficit hyperactivity disorder (ADHD), rage attacks, sleeping disturbances, and depressive symptoms in a Danish clinical cohort of 314 children with TS using validated diagnostic instruments. For the assessment of symptoms of seasonal affective disorder and stuttering, we used a nonvalidated systematic interview. In total, only 10.2% of the children did not have any comorbid symptoms at all. If ADHD and/or obsessive-compulsive disorder were present, the rates of the comorbidities rage, symptoms of seasonal affective disorder, sleep disturbances, and depressive symptoms were significantly higher than if ADHD and/or obsessive-compulsive disorder were absent. The most severe tics were found in the group for which both ADHD and obsessive-compulsive disorder were present. Furthermore, there was a tendency toward more severe tics if other comorbid symptoms were present.