Abstract
The course of obsessive-compulsive disorder (OCD) is variable, ranging from episodic to chronic. We hypothesised that the former course is more likely to be related to bipolar mood disorders. With the use of a specially constructed OCD questionnaire, we studied 135 patients fulfilling DSM-III-R criteria for OCD with an illness duration of at least 10 years and divided by course: 27.4% were episodic and 72.6% chronic. We compared clinical and familial characteristics and comorbidity. Univariate analyses showed that episodic OCD had a significantly lower rate of checking rituals and a significantly higher rate of a positive family history for mood disorder. Multivariate stepwise discriminant analysis revealed a positive and significant relationship between episodic course, family history for mood disorders, lifetime comorbidity for panic and bipolar-II disorders, late age at onset and negative correlation with generalized anxiety disorder. These data suggest that the episodic course of OCD has important clinical correlates which are related to cyclic mood disorders. This correlation has implications for treatment and research strategies on the aetiology within a subpopulation of OCD.