Time to Reconsider Monoamine Oxidase Inhibitors for Obsessive Compulsive Disorder?: A Case Series Using Phenelzine

Despite the availability of a range of efficacious evidence-based treatments for obsessive-compulsive disorder (OCD), not all patients experience sufficient benefit or are able to tolerate them in practice. Monoamine oxidase inhibitors (MAOIs) show efficacy in the treatment of depression and certain anxiety disorders (such as social anxiety disorder).

We survey the evidence base from case reports, and clinical trials, regarding use of MAOIs in OCD. We then present new data from a case series collected in routine clinical practice in a specialist clinical service.

In 9 treatment-resistant patients whose OCD had not improved with at least 2 standard treatment trials, 3 had marked clinical improvement (>35% improvement on YBOCS) on phenelzine, 3 had some improvement (15-34.9%), and 3 showed minimal or no improvement (<15%). In the 3 patients who experienced minimal/no improvement, 2 had discontinued early because of lack of tolerability, and the other patient discontinued after 4 weeks because of perceived lack of symptom benefit.

We suggest that (1) MAOIs in treatment-resistant OCD require appropriate research scrutiny in large-scale randomized controlled trials; and (2) MAOIs merit consideration as a treatment option in individual cases of OCD, particularly in specialist settings where first-line interventions have proven inadequate to manage severe symptoms.