Predictors of response to pharmacotherapy with citalopram in obsessive-compulsive disorder

Although serotonin reuptake inhibitors (SRIs) are the medications of choice in the treatment of obsessive-compulsive disorder (OCD), only 50-60% of pa tients respond to a single trial of any of these agents. Improved knowledge of the predictors of response to treatment may have important clinical imp lications. Data from a large randomized placebo-controlled trial of citalop ram in OCD was analysed using logistic regression to determine predictors o f response. Demographic (age, sex), clinical (OCD severity and duration, de pression severity, prior treatment) and trial variables (citalopram dose, t reatment duration) were included. Subjects with longer duration of OCD, mor e severe OCD symptoms or previous selective SRI use were less likely to be responders in the citalopram trial. In contrast, subjects who received adeq uate medication doses for sufficient periods of time in the citalopram tria l were more likely to be responders. Despite greater awareness of OCD in re cent years, there is evidence that the disorder continues to be underdiagno sed and undertreated. The data here emphasize the crucial importance of ear ly diagnosis and treatment of OCD, and of pharmacotherapy with appropriate dose and duration.(C) 2001 Lippincott Williams & Wilkins.