Recruiting

NAC

Sponsor:

Centre for Addiction and Mental Health

Code:

NCT05142735

Conditions

Prodromal Schizophrenia

Eligibility Criteria

Sex: All

Age: 16 - 35

Healthy Volunteers: Not accepted

Interventions

N-Acetylcysteine

Placebo

Study Details

Brief summary:

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.

Conditions

Prodromal Schizophrenia

Study ID

NCT05142735

Start date

Jan 13, 2023

Status verified date

Mar, 2026

Completion date

Dec 31, 2026

Anticipated

Primary completion date

Nov 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 16 - 35

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. meeting Criteria of Psychosis-Risk Syndromes (COPS) criteria on the Structured Interview for Psychosis-Risk Syndromes (SIPS)
2. capacity to provide informed consent
3. 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 Criteria:

1. 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)
2. concomitant or past neurological condition
3. visual impairment which is not corrected to normal by prescription glasses history of reading disability
4. past antipsychotic treatment at a therapeutic dose
5. current treatment with a psychotropic medication except antidepressants on which the participants has been on a stable dose for at least 30 days.
6. pregnancy (as identified on self-report and/or rapid urine pregnancy test) or intent to become pregnant according to self-report
7. breastfeeding or plan to do so
8. history of kidney stones
9. current treatment with an antibiotic
10. current treatment with nitroglycerin
11. allergy to any ingredients in either the investigational product or placebo product

Study Design

Enrollment

90 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Experimental

N-Acetylcysteine 2000 mg (4 x 500-mg tablets) orally every morning for 8 weeks

placebo comparator: Placebo Comparator

N-Acetylcysteine Placebo tablet matching N-Acetylcysteine orally every morning for 8 weeks

Interventions

N-Acetylcysteine

2000 mg (4 x 500-mg tablets) every morning

Placebo

4 placebo tablets every morning

Primary outcome measure

  • Change in positive psychosis-like symptoms from baseline to 8 weeks [ Time Frame: Week 0 to week 8 ]

Central Contacts and Locations

Central contacts

Locations

Centre for Addiction and Mental Health

Recruiting

Toronto, Ontario, Canada, M5T 1R8

Contacts

More Information

Sponsor

Centre for Addiction and Mental Health

Last update posted

Mar 27, 2026

Last verified

Mar, 2026

Keywords

  • psychosis
  • schizophrenia
  • N-acetylcysteine
  • prodrome
  • mismatch negativity
  • event-related potentials
  • clinical high risk state

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Centre for Addiction and Mental Health on 2026-03-27.