A randomized controlled trial of cognitive therapy versus intensive behavior therapy in obsessive compulsive disorder

Background. The study was designed to compare cognitive therapy (CT) with i ntensive behavior therapy (BT) in obsessive-compulsive disorder (OCD) and t o study their change process. Methods: Sixty-five outpatients with DSM-4 OC D were randomized into 2 groups for 16 weeks of individual treatment in 3 c enters. Group 1 received 20 sessions of CT. Group 2 received a BT program o f 20 h in two phases: 4 weeks of intensive treatment (16 h), and 12 weeks o f maintenance sessions (4 h). No medication was prescribed. Results: Sixty- two patients were evaluated at week 4, 60 at week 16 (post-test), 53 at wee k 26 and 48 at week 52 (follow-up). The response rate was similar in the 2 groups. The Beck Depression Inventory (BDI) was significantly more improved by CT (p = 0.001) at week 16. The baseline BDI and Obsessive Thoughts Chec klist scores predicted a therapeutic response in CT, while the baseline BDI score predicted a response in BT. At week 16, only the changes in Yale-Bro wn Obsessive-Compulsive Scale (Y-BOCS) and a scale measuring the interpreta tion of intrusive thoughts correlated in CT, while the changes in Y-BOCS, B DI, and interpretation of intrusive thoughts correlated in BT. Improvement was retained at follow-up without a between-group difference. The intent-to -treat analysis (last observation carried forward) found no between-group d ifferences on obsessions, rituals and depression, Conclusions: CT and BT we re equally effective on OCD, but at post-test CT had specific effects on de pression which were stronger than those of BT. Pathways to improvement may be different in CT and BT. The outcomes are discussed in the light of an ef fect size analysis. Copyright (C) 2001