The relationship between types and severity of repetitive behaviors in Gilles de la Tourette's disorder and obsessive-compulsive disorder

Background: This study investigated which categories of obsessive-compulsiv e and Tourette-related behaviors in Gilles de la Tourette's disorder and ob sessive-compulsive disorder (OCD) without ties are experienced as most seve re across the study groups and what the differences are in symptom distribu tion between the study groups. Method: Fourteen subjects with both Tourette's disorder and OCD, 18 subject s with Tourette's only, 21 subjects with OCD (no ties), and 29 control subj ects were studied using a semistructured interview designed to equally asse ss Tourette- and OCD-related behaviors according to DSM-III-R criteria. Eac h reported repetitive behavior was evaluated on the presence of anxiety and on goal-directedness. Anxiety-related items were categorized as obsessions or compulsions and non-anxiety-related items as impulsions. Severity of ea ch reported item was assessed with respect to time per day consumed and amo unt of distress and interference induced by the item. Following these crite ria, each reported item was classified as a symptom, a subthreshold symptom , or just as being present. Results: Across the study groups, obsessions were experienced as more sever e than (Tourette-related) impulsions and compulsions. Within the study grou ps, patients with both Tourette's disorder and OCD reported more symptomati c Tourette-related impulsions, such as mental play, echophenomena, and impu lsive or self-injurious behaviors; less overall symptomatic obsessions; and less symptomatic washing than patients with OCD (no ties). The differences among individuals with Tourette's with or without OCD reflected difference s in symptom severity rather than differences in symptom distribution. Conclusion: Obsessions are more time consuming, distressing, and interferin g than compulsions and impulsions. Furthermore, the symptomatic repetitive behaviors were distributed differently among patients with both Tourette's disorder and OCD and patients with OCD (no Lies). Patients with Tourette's and OCD are phenomenologically more similar to Tourette's than to OCD. Thes e differences possibly represent differences in underlying pathophysiology between Tourette's and tie-free OCD.