Sir: Many patients with obsessive-compulsive disorder (OCD) considered to be treatment refractory have prematurely discontinued serotonin reuptake inhibitors (SRIs) due to side effects (such as irritability and anxiety) and are not truly treatment refractory. Some OCD patients intolerant of SRIs had decreased adverse effects after pretreatment with valproic acid. We therefore pretreated an OCD patient intolerant of standard doses of fluoxetine, sertraline, and clomipramine with valproic acid.