Background Obsessive-compulsive disorder (OCD) is a heterogeneous and disabling condition; however, no studies have examined symptom categories or subtypes as predictors of long-term clinical course in adults with primary OCD. Method A total of 213 adults with DSM-IV OCD were recruited from several mental health treatment sites between July 2001 and February 2006 as part of the Brown Longitudinal Obsessive Compulsive Study, a prospective, naturalistic study of treatment-seeking adults with primary OCD. OCD symptoms were assessed annually over the 5-year follow-up period using the Longitudinal Interval Follow-Up Evaluation. Results Thirty-nine percent of participants experienced either a partial (22.1%) or a full (16.9%) remission. Two OCD symptom dimensions impacted remission. Participants with primary obsessions regarding overresponsibility for harm were nearly twice as likely to experience a remission (P < .05), whereas only 2 of 21 participants (9.5%) with primary hoarding achieved remission. Other predictors of increased remission were lower OCD severity (P < .0001) and shorter duration of illness (P < .0001). Fifty-nine percent of participants who remitted subsequently relapsed. Participants with obsessive-compulsive personality disorder were more than twice as likely to relapse (P < .005). Participants were also particularly vulnerable to relapse if they experienced partial remission versus full remission (70% vs 45%; P < .05). Conclusions The contributions of OCD symptom categories and comorbid obsessive-compulsive personality disorder are critically important to advancing our understanding of the prognosis and ultimately the successful treatment of OCD. Longer duration of illness was also found to be a significant predictor of course, highlighting the critical importance of early detection and treatment of OCD. Furthermore, having full remission as a treatment target is an important consideration for the prevention of relapse in this disorder.

The relationship between obsessive-compulsive disorder (OCD) and body dysmorphic disorder (BDD) is unclear. BDD has been proposed to be an OCD-spectrum disorder or even a type of OCD. However, few studies have directly compared these disorders' clinical features. We compared characteristics of subjects with OCD (n = 210), BDD (n = 45), and comorbid BDD/OCD (n = 40). OCD and BDD did not significantly differ in terms of demographic features, age of OCD or BDD onset, illness duration, and many other variables. However, subjects with BDD had significantly poorer insight than those with OCD and were more likely to be delusional. Subjects with BDD were also significantly more likely than those with OCD to have lifetime suicidal ideation, as well as lifetime major depressive disorder and a lifetime substance use disorder. The comorbid BDD/OCD group evidenced greater morbidity than subjects with OCD or BDD in a number of domains, but differences between the comorbid BDD/OCD group and the BDD group were no longer significant after controlling for BDD severity. However, differences between the comorbid BDD/OCD group and the OCD group remained significant after controlling for OCD severity. In summary, OCD and BDD did not significantly differ on many variables but did have some clinically important differences. These findings have implications for clinicians and for the classification of these disorders.

The demographics, clinical characteristics, comorbidity rates, and symptom presentation of the sample are consistent with those reported for cross-sectional studies of OCD, including the DSM-IV Field Trial. The current sample has a number of advantages over previously collected prospective samples of OCD in that it is large, diagnostically well characterized, recruited from multiple settings, and treatment seeking. This unique data set will contribute to the identification of meaningful phenotypes in OCD based on stability of symptom dimensions, prospective course patterns, and treatment response.