Treatment of obsessions: a randomized controlled trial.
This study tested Rachman's cognitive behavioral method for treating obsessions not accompanied by prominent overt compulsions. The cognitive behavioral treatment was compared to waitlist control and an active and credible comparison of stress management training (SMT). Of the 73 adults who were randomized, 67 completed treatment, and 58 were available for one-year follow-up. The active treatments, compared to waitlist, resulted in substantially lower YBOCS scores, OCD-related cognitions and depression as well as improved social functioning. Overall, CBT and SMT showed large and similar reductions in symptoms. Pre-post effect sizes on YBOCS Obsessions for CBT and SMT completers was d = 2.34 and 1.90, respectively. Although CBT showed small advantages over SMT on some symptom measures immediately after treatment, these differences were no longer apparent in the follow-up period. CBT resulted in larger changes on most OCD-related cognitions compared to SMT. The cognitive changes were stable at 12 months follow-up, but the differences in the cognitive measures faded. The robust and enduring effects of both treatments contradict the long-standing belief that obsessions are resistant to treatment.