N-Acetyl Cysteine in the Treatment of Obsessive Compulsive and Related Disorders: A Systematic Review

Abstract

ObjectiveObsessive compulsive and related disorders are a collection of debilitating psychiatric disorders in which the role of glutamate dysfunction in the underpinning neurobiology is becoming well established. N-acetyl cysteine (NAC) is a glutamate modulator with promising therapeutic effect. This paper presents a systematic review of clinical trials and case reports exploring the use of NAC for these disorders. A further objective was to detail the methodology of current clinical trials being conducted in the area.MethodsPubMed, Web of Science and Cochrane Library Database were searched for human clinical trials or case reports investigating NAC in the treatment of obsessive compulsive disorder (OCD) or obsessive compulsive related disorders. Researchers with known involvement in NAC studies were contacted for any unpublished data.ResultsFour clinical trials and five case reports/series were identified. Study durations were commonly 12-weeks, using 2,400–3,000 mg/day of NAC. Overall, NAC demonstrates activity in reducing the severity of symptoms, with a good tolerability profile and minimal adverse effects. Currently there are three ongoing randomized controlled trials using NAC for OCD (two adults and one pediatric), and one for excoriation.ConclusionEncouraging results have been demonstrated from the few pilot studies that have been conducted. These results are detailed, in addition to a discussion of future potential research.

N-Acetyl Cysteine (NAC) in the Treatment of Obsessive-Compulsive Disorder: A 16-Week, Double-Blind, Randomised, Placebo-Controlled Study

“…This may be mediated through the glutamate pathway modulation and in part by reduction of oxidative stress [21]. Our recent systematic review exploring NAC for OCD and OCD-related disorders (OCRD) [38] found that the balance of evidence (mainly case studies) supported the use of NAC in presentations of moderate-severity OCD and OCRD. Doses of 2.4-3 g/day for a minimum of 8 weeks were considered adequate for exerting an initial therapeutic effect.…”

“…First, the sample size was modest and a larger sample may have been powered to detect a smaller effect. It is challenging to recruit an OCD population, and a previous NAC OCD RCT conducted by Pittenger et al from Yale, was abandoned due to recruitment challenges [38]. Interestingly, several participants were difficult to rate on the YBOCS due to severity and complexity of illness, and obsessive 'scrupulosity' affecting reporting fidelity.…”

Avances en el tratamiento farmacológico del trastorno obsesivo-compulsivo.

“…En uno de ellos la combinación de fluvoxamina más NAC fue más eficaz que la de fluvoxamina y placebo en disminuir la sintomatología de pacientes con TOC moderado a severo (52); en el otro estudio, el agregar la NAC al farmacoterapia con ISRS resultó significativamente mejor que adicionar placebo en pacientes con TOC resistente (53). Asimismo, una revisión sistemática sostiene que la NAC reduce la severidad de los síntomas del TOC y trastornos relacionados con un buen perfil de tolerabilidad y mínimos efectos adversos (54). Sin embargo, otro EADCCP no indica resultados concluyentes (55).…”

Antioxidant sulfur compounds: potential therapies for autism?

“…Other trials have shown that n-acetylcysteine as an adjunct to risperidone is more effective at reducing irritability than risperidone alone [32,33]. N-acetylcysteine has also been studied in Obsessive Compulsive Disorder (OCD) and trials in this context have found that it reduces severity of symptoms [34]. As OCD has some overlap with autism symptomatically and as three of the four trials in autism found efficacy for n-acetylcysteine for irritability relative to placebo or as an adjunct, these data broadly support the hypothesis that n-acetylcysteine does have efficacy in autism.…”