Psychopharmacology of comorbid obsessive-compulsive disorder and depression.

A high degree of comorbidity appears to exist between obsessive-compulsive disorder (OCD) and depression, both with respect to symptomatology and at the syndromal level. It has been argued that nonspecific effects on dysphoric mood, anxiety, and depressive symptoms account for the therapeutic efficacy of antidepressants in OCD. However, several controlled studies have shown that neither the presence nor initial severity of depression has any impact on therapeutic improvement in OCD. In particular, studies with the serotonin selective reuptake inhibitors (SSRIs) fluvoxamine and fluoxetine have revealed beneficial effects in OCD, irrespective of the presence of depressive symptoms. The efficacy of the other SSRIs in OCD requires further study. In conclusion, the improvement in OC symptoms seen with fluvoxamine and fluoxetine does not depend on concomitant affective disorder.