Introduction
Obsessive-compulsive disorder (OCD) is the fourth most prevalent mental disorder and is a disabling condition. OCD is associated with anatomical and functional changes in the brain, in addition to dysfunctional cognitions. The treatments of choice are selective serotonin reuptake inhibitors, cognitive-behavioral therapy (CBT), and exposure and response prevention (ERP). Trial-based cognitive therapy (TBCT) is a recent and empirically validated psychotherapy with a focus on restructuring dysfunctional negative core beliefs (CBs). The objective of this study was to evaluate the efficacy of TBCT relative to ERP for treatment of OCD.

Methods
A randomized, single-blind clinical trial was conducted, randomizing 26 patients for individual treatment with TBCT (n = 12) or ERP (n = 14). The groups were evaluated at baseline, at the end of 3 months (12 sessions), and at 3, 6, and 12-month follow-ups.

Results
Both approaches reduced the severity of symptoms with large effect sizes. These results were maintained at the 12-month follow-up assessment.

Conclusion
TBCT may be a valid and promising treatment for this disorder.