Cognitive therapy versus fluvoxamine as a second-step treatment in obsessive-compulsive disorder nonresponsive to first-step behavior therapy.

To compare the effectiveness of second-step treatment with cognitive therapy (CT) versus fluvoxamine in patients with obsessive-compulsive disorder (OCD) who are nonresponsive to exposure in vivo with response prevention (ERP). A 12-week randomized controlled trial at an outpatient clinic in the Netherlands comparing CT with fluvoxamine in OCD. Of 118 subjects with OCD treated with 12 weeks of ERP, 48 appeared to be nonresponders (Y-BOCS improvement score of less than one third). These nonresponders were randomized to CT (n = 22) or fluvoxamine (n = 26). The main outcome measure was the Y-BOCS severity scale. Statistical analyses were conducted in the intention-to-treat sample (n = 45) on an 'as randomized basis' and in the per-protocol sample (n = 30). Due to selective dropout in the fluvoxamine group, two additional sensitivity analyses were performed. Complete data could be obtained from 45 subjects (94%) after 12 weeks. Fifty percent of the patients refused fluvoxamine after randomization compared to 13% who refused CT [χ(2)(1) = 7.10; p = 0.01]. CT as a second-step treatment did not appear to be effective in this sample of nonresponders. Fluvoxamine was significantly superior to CT in the intention-to-treat sample, in the per-protocol sample and in the two separately defined samples in which the sensitivity analyses were performed. OCD patients who are nonresponsive to ERP may benefit more from a switch to treatment with an antidepressant instead of switching to CT. In clinical practice, it may be important to motivate this subgroup of patients to undergo psychopharmacological treatment, as this may improve their outcome considerably.