The Relationship Between Types and Severity of Repetitive Behaviors in Gilles de la Tourette's Disorder and Obsessive-Compulsive Disorder

Background: This study investigated whichcategories of obsessive-compulsive and Tourette-related behaviorsin Gilles de la Tourette’s disorder and obsessive-compulsivedisorder (OCD) without tics are experienced as most severe acrossthe study groups and what the differences are in symptomdistribution between the study groups.

Method: Fourteen subjects with both Tourette’sdisorder and OCD, 18 subjects with Tourette’s only, 21 subjectswith OCD (no tics), and 29 control subjects were studied using asemistructured interview designed to equally assess Tourette- andOCD-related behaviors according to DSM-III-R criteria. Eachreported repetitive behavior was evaluated on the presence ofanxiety and on goal-directedness. Anxiety-related items werecategorized as obsessions or compulsions and non-anxiety-relateditems as impulsions. Severity of each reported item was assessedwith respect to time per day consumed and amount of distress andinterference induced by the item. Following these criteria, eachreported item was classified as a symptom, a subthresholdsymptom, or just as being present.

Results: Across the study groups, obsessionswere experienced as more severe than (Tourette-related)impulsions and compulsions. Within the study groups, patientswith both Tourette’s disorder and OCD reported more symptomaticTourette-related impulsions, such as mental play, echophenomena,and impulsive or self-injurious behaviors; less overallsymptomatic obsessions; and less symptomatic washing thanpatients with OCD (no tics). The differences among individualswith Tourette’s with or without OCD reflected differences insymptom severity rather than differences in symptom distribution.

Conclusion: Obsessions are more time consuming,distressing, and interfering than compulsions and impulsions.Furthermore, the symptomatic repetitive behaviors weredistributed differently among patients with both Tourette’sdisorder and OCD and patients with OCD (no tics). Patients withTourette’s and OCD are phenomenologically more similar toTourette’s than to OCD. These differences possibly representdifferences in underlying pathophysiology between Tourette’s andtic-free OCD.