Rapid Symptom Reduction Following Intramuscular Ketamine in Refractory Obsessive-Compulsive Disorder: A Case Report

Obsessive-compulsive disorder (OCD) is a chronic psychiatric condition that frequently presents with comorbid depressive disorders. For patients exhibiting treatment-refractory OCD and concurrent depressive disorder(s), there is growing clinical interest in the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine as a rapid-acting intervention. This case report describes a 27-year-old female patient with severe, treatment-refractory OCD and comorbid depressive symptoms, detailing her response to a single intramuscular (IM) ketamine administration.

The patient's primary compulsion was that of handwashing, which she would partake in for ~6 h per handwashing session at the time of the first ketamine administration. This occurred daily over a 3.5-month period, wherein a single day would consist of up to 18 total hours of handwashing. These extreme compulsions resulted in severe in-home isolation, precluding in-person psychotherapy and employment. Despite ongoing management by an independent telepsychiatrist, the patient reported no symptom relief from her prescribed regimen of fluoxetine (80 mg) and alprazolam (1 mg, four times daily)-a pharmacotherapeutic approach that may have been clinically suboptimal given the potential for high-dose benzodiazepines to exacerbate obsessive-compulsive symptoms. Given the severity of her condition, she subsequently pursued treatment at an unaffiliated outpatient ketamine clinic.

Following a single IM ketamine administration, the patient experienced an acute, ~97% reduction in handwashing duration (from 6 h sessions to 5-10 min sessions) sustained over a 10-day period. This observation highlights an acute change in the patient's primary compulsive behavior. However, concurrent pharmacotherapy may confound the results, and prospective controlled trials are required to fully evaluate the efficacy of this intervention.