Abstract
Background and Objectives: Obsessive-compulsive disorder (OCD) is a disabling condition with a lifetime prevalence of approximately 2 - 3% in the general population. This paper presents the first controlled study that examines the effects of CBT compared with MCT in the treatment of OCD. Methods: This paper presents an experimental study carried out individually with group-level comparison. Using a parallel design, participants were randomly assigned to either CBT or MCT. The study was conducted in the psychiatric clinic of Imam Hossein Hospital in Tehran, Iran. Of the 47 participants who were assessed, 27 started treatment (CBT = 13, MCT = 14), and 24 were available for a three-month follow-up. Participants were randomly assigned to either 10 weeks of CBT or MCT. Results: Clinically significant changes on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) using Jacobson methodology/Asymptomatic criteria as the index of outcome were 16.7%/0% and 66.7%/41.7% in CBT and MCT, respectively. With respect to Y-BOCS, the effect sizes of MCT (3.28) at post-test and one-month follow-up were higher than that of CBT (1.66). Although both interventions were efficacious in reducing disorder severity, improving QoL, and functioning at post-test, MCT was statistically and clinically more significant. Both interventions led to equally high reductions in depression and anxiety that were apparent in the two follow-ups. Symptom reduction on the Y-BOCS was stable or slightly improving in MCT; however, recovery rates in CBT declined. Conclusions: It is possible that change in MCT occurs through more direct alteration in the brain’s executive function (EF) and modification of EF inputs, addressing a major problem of OCD. Further replication is required as MCT offers a promising alternative treatment approach.