The Brown Longitudinal Obsessive Compulsive Study: Clinical features and symptoms of the sample at intake

Objective: This article describes the method and intake findings of the Brown Longitudinal Obsessive Compulsive Study, the first comprehensive prospective investigation of the naturalistic course of obsessive-compulsive disorder (OCD) in a large clinical sample using longitudinal research methodology. Method: Intake data, collected between June 2001 and October 2004, are presented for 293 adult participants in a prospective, naturalistic study of OCD. Participants had a primary diagnosis of DSM-IV OCD and had sought treatment for the disorder. Results: Our findings indicate that OCD typically has a gradual onset and a continuous course regardless of age at onset. There is a substantial lag between the onset of the disorder and initiation of treatment. OCD, which almost always coexists with other psychiatric symptoms, leads to serious social and occupational impairment. Compared with participants with late-onset OCD, early-onset participants had higher rates of lifetime panic disorder, eating disorders, and obsessive-compulsive personality disorder. The groups also differed on the types of obsessive-compulsive symptoms that were first noticed, as well as on rates of current obsessions and compulsions. Conclusion: 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.