Background: Very few studies have compared the efficacy of individual and group cognitive behaviour therapy (CBT) for the treatment of Obsessive-Compulsive Disorder (OCD) by taking into consideration the change in OCD severity in both the short and long term. Aims: To conduct an open trial of individual versus group CBT for OCD, comparing the clinical and statistically significant changes in severity both at post-treatment and one year later. Method: Forty-two OCD subjects were assigned to individual (n = 18) or group CBT (n = 24, in four groups). Sixteen and 22 subjects completed the treatment in the individual and group conditions, respectively. The Yale-Brown Obsessive Compulsive Scale was recorded at pre-treatment, post-treatment and at the one-year follow-up. Results: At the end of treatment, the clinically significant change was comparable for the two treatment conditions and remained stable at the one-year follow-up. Of the 16 participants who completed the individual CBT treatment, 68.75% were classified as recovered at post-treatment, compared to 40.9% of those receiving group CBT. At follow-up the rate of recovery decreased to 62.5% in individual CBT and to 31.8% in group CBT. Conclusions: Group CBT is effective in decreasing OCD severity. The post-treatment changes were maintained one year later. Nevertheless, these changes were higher in the individual delivery of CBT.

The aim of the study was to assess the effectiveness of cognitive group therapy compared to a waiting list in a sample of patients with heterogeneous non-psychotic disorders. Participants in this study were referred from either the psychiatric in- or outpatient clinic at the psychiatric university hospital in Trondheim, Norway. The patients were assessed with SCID I and SCID II, and randomized either to cognitive group therapy (n=15) or to a waiting list (n=17). Self-report assessments of symptoms and interpersonal difficulties were administered at the start of therapy, after termination of therapy (8 weeks), and at 6 months and 12 months follow-up. Thirty-two patients completed 8 weeks of therapy. Results showed that an 8-week program of CBGT performed better than the waiting list controls, on symptom relief at post-treatment for all patients. The effects of therapy were still upheld at 6 and 12 months follow-up. Cognitive therapy seems to be useful and effective in a group format in naturalistic clinical settings, with patients suffering from various forms of non-psychotic co-morbid psychiatric disorders.