N-acetylcysteine augmentation in treatment resistant obsessive compulsive disorder: A case series

BackgroundEvidence-based, first-line treatments for obsessive compulsive disorder, (OCD) include the serotonin reuptake inhibitors (SRI), however, 40–60% of OCD patients do not respond. A wide variety of agents have been examined as adjuncts to standard SRI treatment in cases of treatment resistance, however, no gold-standard approach has been identified. Glutamate dysfunction is now thought to have a role in OCD, and use of glutamatergic treatment agents may hold promise. N-acetylcysteine (NAC) is an amino acid derivative of cysteine, available as a health supplement. It has shown efficacy in OCD-spectrum disorders and in 1 case report of treatment resistant OCD.MethodA retrospective chart review of 6 treatment resistant OCD patients, who had been treated with NAC for 6–12 weeks. Symptom severity was evaluated at regular clinic visits.ResultsFive of 6 patients took NAC for 12 weeks. The mean endpoint dose was 2833.3±408.2mg/day. Only 1/6 patients responded to treatment with NAC; two patients reported a worsening of symptoms; no patients reported adverse events.ConclusionsNAC was not effective in this sample of treatment-refractory OCD patients. Whether this result was a function of the mechanism of action of NAC or of the pathophysiology of treatment refractory OCD, remains unclear.