While exposure and response prevention (ERP) and cognitive behavioral therapy (CBT) are effective for treating OCD, some patients do not experience a reduction in symptoms. In animal models, d-cycloserine has been shown to increase glycine activity in the NMDA receptor, which helped with learning fear extinction.
This study by Dr. Kushner and his team aimed to understand whether d-cycloserine could help people with OCD become more receptive to ERP+CBT by administering 125 mg of d-cycloserine to 15 participants with OCD and placebo for 17 participants with OCD two hours before each of ten ERP+CBT sessions. The results showed that D-cycloserine reduced the number of ERP+CBT sessions needed to achieve notable symptom decrease to four, with the placebo group catching up to this level of decrease after more sessions (Kushner et al., 2007). This study contributed to the growing literature around D-cycloserine and its effects for augmenting ERP+CBT, yet a systematic review of 21 trials (Mataix-Cols et al., 2016) showed that D-cycloserine generally can make a small improvement to therapy and stressed the need for further research.
*Mataix-Cols, D., Fernández de la Cruz, L., Monzani, B., Rosenfield, D., Andersson, E., Pérez-Vigil, A., Frumento, P., de Kleine, R. A., Difede, J., Dunlop, B. W., Farrell, L. J., Geller, D., Gerardi, M., Guastella, A. J., Hofmann, S. G., Hendriks, G. J., Kushner, M. G., Lee, F. S., Lenze, E. J., Levinson, C. A., … Thuras, P. (2017). D-Cycloserine Augmentation of Exposure-Based Cognitive Behavior Therapy for Anxiety, Obsessive-Compulsive, and Posttraumatic Stress Disorders: A Systematic Review and Meta-analysis of Individual Participant Data. JAMA Psychiatry, 74(5), 501–510. doi:10.1001/jamapsychiatry.2016.3955
*Kushner, M.G., Kim, S.W., Donahue, C., Thuras, P., Adson, D., Kotlyar, M., McCabe, J., Peterson, J., & Foa, E.B. (2007). D-cycloserine augmented exposure therapy for obsessive-compulsive disorder. Biological Psychiatry, 62, 835-838. doi:10.1016/j.biopsych.2006.12.020