Personality traits and treatment outcome in obsessive-compulsive disorder.

OBJECTIVE Comorbidity with personality disorders in obsessive-compulsive patients has been widely reported. About 40% of obsessive-compulsive patients do not respond to first line treatments. Nevertheless, there are no direct comparisons of personality traits between treatment-responsive and non-responsive patients. This study investigates differences in personality traits based on Cloninger's Temperament and Character Inventory scores between two groups of obsessive-compulsive patients classified according to treatment outcome: responders and non-responders. METHOD Forty-four responsive and forty-five non-responsive obsessive-compulsive patients were selected. Subjects were considered treatment-responsive (responder group) if, after having received treatment with any conventional therapy, they had presented at least a 40% decrease in the initial Yale-Brown Obsessive Compulsive Scale score, had rated "better" or "much better" on the Clinical Global Impressions scale; and had maintained improvement for at least one year. Non-responders were patients who did not achieve at least a 25% reduction in Yale-Brown Obsessive Compulsive Scale scores and had less than minimal improvement on the Clinical Global Impressions scale after having received treatment with at least three selective serotonin reuptake inhibitors (including clomipramine), and at least 20 hours of cognitive behavioral therapy. Personality traits were assessed using Temperament and Character Inventory. RESULTS Non-responders scored lower in self-directedness and showed a trend to score higher in persistence than responders did. CONCLUSION This study suggests that personality traits, especially self-directedness, are associated with poor treatment response in obsessive-compulsive patients.