Translational Approach to the Understanding and Treatment of Obsessive-Compulsive Disorder (OCD). Can D-Cycloserine Enhance and Stabilize the Treatment-response in Relapsed and Non-responding OCD-patients?

In this randomized controlled trial (RCT) the investigators experimentally test if patients with Obsessive-Compulsive Disorder (OCD) who have received treatment with exposure and response prevention (ERP), but either relapsed or not responded, profit from the combination of concentrated exposure based treatment (cET) and the NMDA-agonist (N-methyl-d-aspartate) d-cycloserine (DCS), targeting fear relevant areas in amygdala and pre-frontal cortex. The project expects to demonstrate a significant improvement in all groups, and anticipate that a higher proportion of the patients who receive DCS will show a better long-term gain from the treatment, as compared to the placebo group at follow-up (3 mon, 12 mon, and 5 years after treatment). In addition, the project will highlight changes in depression, sleep, global functioning, quality of life, work and social status. Changes in medication and use of health care will be included and related to the main objective of the study.