Randomized comparative study of group versus individual cognitive behavioural therapy for obsessive compulsive disorder

Abstract

The primary aim of the study was to compare the effectiveness of group and individual cognitive behaviour therapy (CBT) for obsessive compulsive disorder (OCD). One hundred and ten out-patients with OCD were randomly assigned to 15 sessions of either group CBT or individual CBT. Outcome measures were administered before and after treatment, as well as at 6- and 12-month follow-ups. The study was supplemented by a meta-analysis of accomplished comparative studies of group vs. individual CBT for OCD. Large and stable pre-post effect sizes were found for both treatment conditions in the study (d = 1.06-1.24 on the Yale-Brown Obsessive Compulsive Scale). There were no significant between-group differences in outcome at any data point (ds= -0.13 to 0.15). The meta-analysis of four accomplished comparative studies (including the present one) found a between-group mean effect size of (d= 0.15 favouring individual over group CBT at posttreatment (95% confidence interval, -0.12, 0.42). The results of this study suggest that OCD can be treated effectively with a group format of CBT, thus sparing some therapist resources, although the four accomplished comparative studies do not rule out the possibility of a small superiority of individually conducted CBT.