Tests N-acetylcysteine for early warning symptoms of schizophrenia

Trial details

Who runs it

Centre for Addiction and Mental Health

Trial code

NCT05142735

Record updated

27 March 2026

Original description

Schizophrenia is a chronic debilitating psychotic disorder. Identifying persons with "clinical high-risk" (CHR) symptoms, which are like those of schizophrenia but less severe, and providing psychiatric care to these individuals has been shown to help prevent psychosis. Current medications used for CHR symptoms, however, are associated with substantial side effect burden. Therefore, practice guidelines do not recommend current medications as routine treatment for the CHR state, and there is a need to identify new treatments for this condition.Read full original descriptionShow less

Effects of N-acetylcysteine on Psychosis-like Symptoms and a Neurophysiological Biomarker of the Clinical High Risk for Schizophrenia

Schizophrenia is a chronic debilitating psychotic disorder. Identifying persons with "clinical high-risk" (CHR) symptoms, which are like those of schizophrenia but less severe, and providing psychiatric care to these individuals has been shown to help prevent psychosis. Current medications used for CHR symptoms, however, are associated with substantial side effect burden. Therefore, practice guidelines do not recommend current medications as routine treatment for the CHR state, and there is a need to identify new treatments for this condition.

Research suggests that abnormal brain oxidative stress may contribute to schizophrenia, offering a potential novel treatment target in the CHR state. Oxidative stress is an excess of free radicals, which are generated from normal metabolism and environmental exposures, and can damage cells. Antioxidants in the body normally neutralize free radicals. Antioxidant deficiency could result in excess oxidative stress that damages brain cells, leading to schizophrenia. Recent studies suggest that N-acetylcysteine (NAC), a precursor of the most abundant brain antioxidant, glutathione, may be a safe, well-tolerated treatment for schizophrenia. In light of this, NAC may also reduce symptoms and brain abnormalities in CHR patients.

Inclusion: meeting Criteria of Psychosis-Risk Syndromes (COPS) criteria on the Structured Interview for Psychosis-Risk Syndromes (SIPS); capacity to provide informed consent; if female, participant is not of child-bearing potential, defined as females who have undergone a sterilization procedure or have been post-menopausal for at least 1 year prior to screening OR participant is of child-bearing potential and agrees to use a medically approved method of birth control for the duration of the study.

Exclusion: concomitant or past neurological condition; current treatment with a psychotropic medication except antidepressants on which the participants has been on a stable dose for at least 30 days; current treatment with an antibiotic; current treatment with nitroglycerin; allergy to any ingredients in either the investigational product or placebo product; meeting criteria for any other DSM-5 diagnosis at the time of the study (except -personality disorder, nicotine use disorder, or other substance use disorder in full remission); visual impairment which is not corrected to normal by prescription glasses history of reading disability; history of kidney stones; past antipsychotic treatment at a therapeutic dose; pregnancy (as identified on self-report and/or rapid urine pregnancy test) or intent to become pregnant according to self-report; breastfeeding or plan to do so.

ClinicalTrials.gov NCT05142735