Participants will attend 90-minute ERP + improv group therapy sessions for 12 consecutive weeks. They will also complete homework between sessions, answer questions, and complete questionnaires.

Therapist-led 90-minute exposure and response prevention (ERP) combined with improv sessions.

Change in OCD severity is measured by the YBOCS (Yale Brown Obsessive-Compulsive Scale), a gold standard measure of obsessions and compulsions. For the YBOCS the minimum units are 0 and Maximum units on the total scale are 40. The higher the number on the YBOCS, the more severe the symptoms. Response is defined as at least a 35% change on the YBOCS.

Change in intolerance of uncertainty (IU) will be measured with the Intolerance of Uncertainty Scale - Short Form (IUS-12). IU is the tendency to respond negatively to uncertain situations. The IUS-12 is a 12-item self-report measure that assesses IU. Each item is assessed using a 5-point Likert scale ranging from 1 (not at all characteristic of me) to 5 (entirely characteristic of me).

It consists of two subscales: Prospective IU and Inhibitory IU. Prospective IU is the cognitive appraisal of a threat related to future uncertainty. Inhibitory IU refers to the behavioral inhibition related to uncertainty. The Prospective IU subscale is comprised of 7 items, while the Inhibitory IU subscale is comprised of 5 items. Scores are summed to generate the two subscale scores and a total score. Total IUS-12 scores range from 12 to 60, with higher scores indicating a higher IU.