N-acetyl-cysteine in a double-blind randomized placebo-controlled trial: Towards biomarker guided treatment in early psychosis

Abstract

PurposeRecent evidence points to a critical role of redox dysregulation induced oxidative stress in the pathophysiology of early phases of schizophrenia. An add-on trial with n-acetyl-cysteine (NAC) led to a reduction in negative symptoms in chronic schizophrenia patients. Aim of this study was to explore impact of addition of NAC to standard treatment in early psychosis (EP) patients.MethodsDouble-blind, randomized, placebo-controlled trial of addition of NAC, 2700 mg daily, to antipsychotic treatment over 6 months. Monthly assessment of PANSS, GAF, SOFAS and antipsychotics treatment; quantification of brain glutathione levels (GSHmPFC) by 1H-magnetic-resonance-spectroscopy and of blood cells glutathione (GSHBC) and glutathione peroxidase activity (GPxBC) as marker of oxidation status at the beginning and end of treatment.ResultsOverall, 63 patients were included. Spectroscopy data showed that GSHmPFC increased by +23% in the NAC group, while it tended to decrease by −5% in the placebo group (P = 0.005). No significant difference between NAC and placebo was observed on global changes in negative symptoms, positive symptoms or functional outcome. However, in patients with high-baseline oxidation status (GPxBC>22.3U/gHb), subgroup explorations revealed an improvement of positive symptoms over time compared to patients with low-baseline GPx (P = 0.02).ConclusionsWhile addition of NAC induced an increase of brain GSH, it had no impact on symptomatic and functional outcome in EP patients. However, in patients with high oxidation status, addition of NAC leads to significantly greater improvement in positive symptoms. Future studies on antioxidant interventions in EP should consider biomarker-guided treatment.Disclosure of interestThe authors have not supplied their declaration of competing interest.