N-acetylcystein (NAC), a precursor to the amino acid cysteine, has been emerging as an interesting add-on treatment in several psychiatric conditions and especially in Obsessive Compulsive Disorder (OCD). These results may be linked to its metabolic profile: antioxidant properties through glutathione production; anti-inflammatory properties; and modulation of the glutamatergic and dopaminergic systems of neurotransmission.

Review the potential therapeutic effects of NAC in psychiatry, with main focus on syndromes of the obsessive-impulsive spectrum with report of a clinical case.

Case report of a patient with OCD and Hoarding disorder, with complete clinical remission after treatment with NAC; bibliographic search using PubMed/MedLine database with the following keywords: n-acetylcysteine; OCD; hoarding.

We report and discuss the case of a 44-year-old man with a diagnosis of Obsessive Compulsive Disorder with orderliness and contamination themes, coupled with Hoarding disorder. The patient experienced gradual though slight improvement with Paroxetine (60 mg/day) to which was subsequently added Risperidone (2 mg/day) with further slight improvement. In combination with the previously given pharmacological agents, NAC (1800 mg/day) was introduced with subsequent complete remission of all symptoms.

Studies suggest that NAC may be useful in the treatment of several psychiatric conditions. Our case report suggests direct relation between treatment with NAC and remission of obsessive and hoarding symptoms. Although encouraging, additional controlled research will be required to ascertain NAC clinical usefulness.