Objective: Little is known about the longitudinal course of symptoms in adult patients with obsessive-compulsive disorder (OCD), although some evidence exists regarding symptom stability in children and adolescents. This study systematically investigated the temporal stability of individual symptoms and symptom dimensions of OCD in adult patients who were followed prospectively for 2 years.
Method: One hundred seventeen adult outpatients with OCD from three U.S. sites were administered the Yale-Brown Obsessive Compulsive Scale symptom checklist four times over a period of 2 years. Eighty-one (69%), 83 (71%), and 67 (57%) patients were available 6 months, 1 year, and 2 years after initial screening, respectively. Different analytic methods assessed the stability of OCD symptoms within and between previously identified symptom dimensions.
Results: For the most part, patients maintained their symptoms throughout follow-up, although some symptoms were more stable than others. For the symptoms that changed, changes occurred within rather than between symptom dimensions; qualitative shifts from one dimension to another were rare. The strongest predictor of the presence of a particular symptom was having had that symptom in the past. Although most patients had received pharmacological and behavioral treatment during the follow-up period, changes within symptom dimensions could not be explained by overall clinical improvement over time.
Conclusions: Symptoms of adult patients with OCD might be more stable across time than previously thought, with some symptoms waxing and waning within symptom dimensions and rarely involving shifts between dimensions. Longer follow-up studies involving larger samples are needed to better understand the fluctuations of OCD symptoms across time.