Ketamine in OCD: Efficacy and Effects on Stress and Cognition

Ketamine Therapy in Obsessive-compulsive Disorder and Its Effects on Neuropsychological Function Under Stress in a Cross-over Trial

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.

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. Also EEG measurements will take place during and before infusions in this phase. Study subjects will be given an option to participate in an open-label follow up with up to 8 infusions over a period of a month. Open-label ketamine treatment will be compared to treatment as usual. After finishing open label treatment an additional EEG measurement will take place.

Inclusion Criteria:

• Primary diagnosis of obsessive-compulsive disorder
• A score of 16 or higher on the Yale-Brown Obsessive Compulsive Scale and ability to provide written informed consent
• At least one previous treatment for OCD

Exclusion Criteria Experimental Group:

• Any history of current or past psychotic disorder
• A manic episode within the preceding three years
• Current or unstable remitted substance abuse or dependence except nicotine
• Pregnancy or elevated risk of becoming pregnant during study duration (desire to have children) and refusal to utilize a proper method of contraception
• Any current severe personality disorder except comorbid anankastic personality disorder
• Morbus Raynaud
• Inability to follow the study protocol or adhere to operational requirements
• Current and unstable suicidality
• Unstable hypertension
• Untreated hyperthyroidism
• Any unstable cardiovascular disease
• Untreated disorders severely affecting the HPA-axis (M.Addison, M.Cushing)
• Current pharmacological therapy severely affecting the HPA-axis like corticosteroids or ACTH

Exclusion Criteria Treatment as Usual Group:

• Any history of current or past psychotic disorder
• A manic episode within the preceding three years
• Current or unstable remitted substance abuse or dependence except nicotine
• Any current severe personality disorder except comorbid anankastic personality disorder
• Current and unstable suicidality