Recruiting

Observational Study

Sponsor:

Douglas Mental Health University Institute

Code:

NCT05445180

Conditions

Psychotic Disorders

Cannabis Use Disorder

Cannabis Dependence

Cannabis Use

Schizophrenia; Psychosis

Eligibility Criteria

Sex: All

Age: 16 - 70+

Healthy Volunteers: Accepted

Interventions

Contingency management

Study Details

Brief summary:

Cognitive impairment is well established in people with psychosis and is associated with cannabis use. The current study will investigate the neurobiological basis of cognitive change associated with 28-days of cannabis abstinence in people with psychosis and non-psychiatric controls with cannabis use. Participants will be randomized to a cannabis abstinent group or a non-abstinent control group and will undergo magnetic resonance imaging at baseline and following 28-days of abstinence. This study will help characterize the neuropathophysiological processes underlying cognitive dysfunction associated with cannabis use and its recovery which may guide the development of novel interventions for problematic cannabis use.

Conditions

Psychotic Disorders

Cannabis Use Disorder

Cannabis Dependence

Cannabis Use

Schizophrenia; Psychosis

Study ID

NCT05445180

Start date

Apr 21, 2022

Status verified date

Aug, 2025

Completion date

May, 2027

Anticipated

Primary completion date

May, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 16 - 70+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Able to provide informed consent in English or French
  • Heavy cannabis use (defined as weekly cannabis use for at six months) and/or DSM-5 diagnosis of CUD
  • Have a Full-Scale IQ ≥ 75
  • Meet DSM-5 criteria for a psychotic disorder (psychosis patient arm only)
  • Be an outpatient receiving a stable dose of medication(s) for at least two months (psychosis patient arm only)
  • Clinically stable (as measured by the PANSS-6, total score <30) (psychosis patient arm only)

Exclusion Criteria:

  • current SUD (other than CUD)
  • MRI contraindications
  • Positive urine screen for psychoactive substances other than cannabis, nicotine, or caffeine
  • Current suicidal or homicidal ideation
  • Head injury requiring hospitalization or loss of consciousness > 5 minutes
  • Current medical diseases that requires hospitalization or regular monitoring
  • Being pregnant
  • DSM-5 Axis 1 diagnosis (other than CUD) (non-psychiatric controls only)
  • Taking psychotropic medication

Study Design

Enrollment

134 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Psychosis patients with cannabis use (Abstinent)

Psychosis patients with cannabis use will receive contingency management to encourage cannabis abstinence for 28 days

no intervention: Psychosis patients with cannabis use (Non-abstinent)

Psychosis Patients with cannabis use who will continue to use cannabis as usual

experimental: Non-Psychiatric controls with cannabis use (Abstinent)

Non-Psychiatric controls with cannabis use will receive contingency management to encourage cannabis abstinence for 28 days

no intervention: Non-Psychiatric controls with cannabis use (Non-abstinent)

Non-Psychiatric Controls with cannabis use will continue to use cannabis as usual

no intervention: Non-Psychiatric Controls without cannabis use

Non-Psychiatric controls without cannabis use

Interventions

Contingency management

Contingency management will be used to encourage abstinence

Primary outcome measure

  • Change in fMRI brain activity pattern [ Time Frame: Baseline, Day 28 ]
  • Change in behavior during fMRI task [ Time Frame: Baseline, Day 28 ]

Central Contacts and Locations

Central contacts

Charlene Osei-Afrifa

(514) 761-6131aimh.research@gmail.com

Locations

Douglas Mental Health University Institute

Recruiting

Montreal, Quebec, Canada, H4H 1R3

Contacts

Research Coordinator

(514) 761-6131aimh.research@gmail.com

Principal Investigator:

Rachel Rabin, Ph. D.

More Information

Sponsor

Douglas Mental Health University Institute

Last update posted

May 22, 2026

Last verified

Aug, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Douglas Mental Health University Institute on 2026-05-22.