This study will apply a randomized, double blind, comparator-controlled cross-over design and will be conducted at the Department of Psychiatry and Psychotherapy of the Medical University of Vienna. We will include 30 participants with a primary diagnosis of OCD. Participants will undergo ketamine and comparator infusions in either inpatient- or outpatient settings to assess the therapeutic capabilities of ketamine in OCD. Furthermore, participants' neurocognitive function and stress responses will be tested with four neurocognitive tasks and a cold pressor test paradigm.
The main goal of this trial is to demonstrate therapeutic efficacy of low dose ketamine in patients with OCD. We expect that ketamine will alleviate symptoms in the hours following application, but also - if effective - that the anti-OCD effects might last for several days after a single infusion.