Does cannabis potency affect brain white matter in early psychosis?

Cannabis Potency Effects on Brain White Matter in Early Phase Psychosis: A Pilot Feasibility Treatment Study

Phase 4 Interventional Nova Scotia Health Authority · NCT07001878

This project will test whether using high- versus low-potency cannabis is linked to differences in brain white matter in young adults (18–25) with early-phase psychosis.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years to 25 Years
SexAll
SponsorNova Scotia Health Authority Academic / other
Locations2 sites (St. John's, Newfoundland and Labrador and 1 other locations)
Trial IDNCT07001878 on ClinicalTrials.gov

What this trial studies

The protocol compares three groups of 18–25-year-olds with early phase psychosis: regular high-potency cannabis users (>15% THC), regular low-potency users (<15% THC), and patients with minimal or no cannabis use. Investigators will collect demographic, clinical, substance-use (using the Timeline Followback and WHO-ASSIST), and neuropsychological measures and will verify self-reported product potency where possible via product websites. Brain white matter will be examined with neuroimaging and related to cannabis use patterns and cognitive performance to look for potency-related differences. The record lists metformin as an intervention, although the central aim is to compare potency-related brain measures across the groups.

Who should consider this trial

Good fit: Ideal candidates are 18–25-year-olds enrolled in the Nova Scotia Early Psychosis Program or the listed Newfoundland site who have varying levels of recent cannabis use.

Not a fit: People with current stimulant use disorder, those outside the 18–25 age range, or not enrolled at the participating programs are unlikely to be eligible or to directly benefit from this study's findings.

Why it matters

Potential benefit: If successful, the findings could help tailor treatment and harm-reduction advice about cannabis use to improve long-term outcomes for young people with early psychosis.

How similar studies have performed: Prior research has linked cannabis use to brain white matter changes and worse outcomes in psychosis, but direct comparisons by product THC potency in early psychosis remain relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* This study will enroll individuals 18-25 years of age from the Nova Scotia Early Psychosis Program

Exclusion Criteria:

* Current stimulant use disorder

Where this trial is running

St. John's, Newfoundland and Labrador and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions PsychosisCannabis Usecannabismetforminearly phase psychosispotency
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.