Objective: It is not clear whether obsessive-compulsive disorder (OCD) in the context of Tourette's syndrome (TS) is the same as that disorder found in patients with OCD alone. This study evaluated the severity and characteristics of the obsessive-compulsive symptoms in adult patients with OCD and TS compared to adult patients with OCD alone.
Method: Thirteen subjects with both DSM-III-R TS and OCD and 13 subjects with OCD alone were recruited. Obsessive-compulsive severity was determined by using the Yale-Brown Obsessive Compulsive Scale. The Tourette Syndrome Association Unified Tic Rating Scale was administered to determine tic severity, and the adult version of the Attention Deficit and Hyperactivity Checklist was used to detect a history of childhood attention-deficit hyperactivity disorder (ADHD).
Results: Subjects with OCD alone had very few obsessions and compulsions that were not also experienced by subjects with both TS and OCD. In contrast, subjects with TS and OCD were significantly more likely to report obsessions involving nonviolent images, excessive concern with appearance, and need for symmetry. Touching, blinking or staring, and counting compulsions were also significantly more common in this group. Eight subjects with OCD and TS had a childhood history of ADHD, compared to none of the pure OCD subjects.
Conclusion: There are subtle but definite differences in symptomatology of subjects with pure OCD compared to those with OCD and TS consistent with putative differences in pathophysiology between the 2 groups, i.e., abnormalities in the serotonergic system in OCD patients and serotonergic and dopaminergic abnormalities in those with OCD and TS. These observations may be consistent with genetic heterogeneity within both OCD and TS.