Effectiveness of Individual Cognitive-Behavioral Therapy and Predictors of Outcome in Adult Patients with Obsessive-Compulsive Disorder.

INTRODUCTION

Cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) has proven its efficacy in randomized controlled trials (RCTs).

OBJECTIVE

To test generalizability to routine care settings, we conducted an effectiveness study to provide naturalistic outcome data and their predictors.

METHODS

Pre-post changes in symptoms and impairment as well as response rates were determined in a naturalistic OCD sample (intention-to-treat, ITT, n = 393). Patients received individual CBT for OCD adopting an exposure-based, non-manualized treatment format. Linear and logistic regression analyses were applied to identify associations of sociodemographic and clinical variables with symptom change.

RESULTS

Effect size in ITT patients amounted to d = 1.47 in primary outcome (Yale-Brown Obsessive-Compulsive Scale, Y-BOCS). Remission rates were 46.3% (ITT), 52.0% (completers), and 18.2% (non-completers). The rates of treatment response without remission, no change, and deterioration in the ITT sample were 13.2, 38, and 3%, respectively. Initial symptom severity, comorbid personality disorder, and unemployment were associated with a poorer outcome, and previous medication with a better outcome. Comorbid depressive and anxiety disorders as well as other clinical or sociodemographic variables showed no effects on symptom change.

CONCLUSIONS

Outcomes in this large observational trial in a naturalistic setting correspond to available RCT findings suggesting that CBT for OCD should be strongly recommended for dissemination in routine care. Targets for further research include early prediction of non-response and development of alternative treatment strategies for patients who respond insufficiently.