Cognitive behaviour therapy for partial responders with OCD: A randomized controlled trial

To examine the relative efficacy of CBT and antipsychotic augmentation (risperidone) in reducing Obsessive Compulsive Symptoms and improving overall functioning and quality of life in partial responders with OCD.

Primary outcome measure is the response to treatment post-therapy. Secondary outcome measures include remission, quality of life, global functioning and improvement in measure of depression and anxiety

Patients will be recruited from the OCD clinic as well as in patient and out patient services of the National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore. Eligible participants fulfilling the criteria for at least partial response to SRIs will be randomized to one of the two study groups CBT (SRI+CBT+risperidone pill placebo), risperidone (SRI+Risperidone+Stress management training) augmentation group. Randomization will be carried out using a computer-generated list. The CBT group will also receive risperidone pill placebo and the risperidone group, the stress management training. In order to control for effects of attention or additional time spent by the researcher in the CBT group patients receiving risperidone will be given instructions in stress management strategies (including Psycho education about OCD, Problem solving skills, Relaxation strategies; Simpson et al., 2008). Those in the CBT group will receive risperidone pill placebo to mask the effect of risperidone.  Participants will continue to receive the SRI medication in both groups, but no changes will be made to SRI medication unless patient develops intolerable side effects or any serious adverse events. Participants will be assessed at baseline, mid-therapy (10 sessions), Post treatment (after about 20 sessions), 3 and 6 months, using the CGI-I, YBOCS, Hamilton Anxiety Rating scale and Hamilton Depression Rating Scale, GAF and the Quality of life and Enjoyment Scale by an independent blinded rater.

The sample size will comprise of 50 patients in each of the two groups, based on selection criteria. The sample size has been calculated using the power analysis. Forty-one subjects will be required in each arm to attain a two-tailed significance of .05 and 80% power with an expected difference in the response rate of about 25% between the groups. A final sample size of 50 in each group will be aimed at taking into consideration drop outs both groups.

There will no additional medications until the completion of study period. Only anticholinergic medications and short acting benzodiazepines/zolpidem may be added for the extrapyramidal symptoms and insomnia respectively. Patients who require major changes in medication during the course of the study will be considered a drop-out.