Participants remain on their current OCD medication and are randomly assigned to receive one of two CBTs: exposure and ritual prevention or stress management therapy. Exposure and ritual prevention involves imaginal and in-vivo exposure and requires that participants refrain from ritualizing. Stress management involves relaxation, assertiveness training, and structured problem-solving. Therapy occurs twice per week for 2 months. Participants are assessed verbally by an independent evaluator and are asked to complete self-rating forms. Patients who respond are followed for up to 1 additional year. Participants continue to take the same medication and the same monthly therapy for the first 6 months of follow-up. During the second 6 months of follow-up, participants discontinue therapy but continue taking the same medication.