Pilot Study of RR-HNK in OCD

Inclusion Criteria: * Ages 18-65 * Meet the criteria for OCD diagnosis * Failed at least 1 prior trial of standard first-line OCD treatment (e.g. SRI/CBT) or or had refused these treatments for individual reasons * Agree to the following lifestyle modifications: comply with requirements for fasting prior to --the infusion session, not enroll in any other interventional clinical trials during the duration of the study, and commit to medication study procedures. * Able to provide informed consent Exclusion Criteria: * Allergy or hypersensitivity to ketamine * Any current or past medical/psychiatric condition that makes participation unsafe in the opinion of the investigator or study physician * Pregnant or nursing, or able to become pregnant and are not practicing an effective means of birth control * Lifetime history of deep brain stimulation