Comprehensive Review Finds Cannabis-Using Psychosis Patients May Be Neurobiologically Different

A systematic review of 70 studies found accumulating evidence that cannabis-using and non-using patients with psychotic disorders may have distinct patterns of neurocognitive and neurodevelopmental impairments.

Sami, Musa Basseer et al.·Journal of psychopharmacology (Oxford·2018·Strong EvidenceSystematic Review
RTHC-01821Systematic ReviewStrong Evidence2018RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Systematic Review
Evidence
Strong Evidence
Sample
N=3,000

What This Study Found

Cannabis use is associated with increased risk of developing psychotic disorders, increased hospitalization, longer hospital stays, and treatment failure. The systematic review of 70 studies (3,000+ patients) found evidence for distinct neurobiological patterns in cannabis-using versus non-using psychosis patients, though the biological underpinnings remain to be fully elucidated.

Key Numbers

70 studies reviewed, over 3,000 patients included. Evidence covers risk of developing psychosis, hospitalization patterns, and treatment response in cannabis-using versus non-using patients.

How They Did This

Two-part approach: summary of longitudinal evidence on cannabis-psychosis associations, plus systematic review of 70 studies examining neurobiological and neurochemical mechanisms in over 3,000 patients with psychotic disorders or at increased risk.

Why This Research Matters

If cannabis-using psychosis patients truly represent a neurobiologically distinct subgroup, they may need different treatment approaches. Understanding these differences could lead to more personalized interventions.

The Bigger Picture

This review makes the case that cannabis is not just a confounding variable in psychosis research but a significant factor that may create distinct clinical and neurobiological profiles. This has implications for both prevention and treatment strategies.

What This Study Doesn't Tell Us

Many included studies were cross-sectional. Establishing causation from observational data is inherently limited. Heterogeneity in cannabis use patterns and psychosis definitions across studies.

Questions This Raises

  • ?Should cannabis-using psychosis patients receive different treatments?
  • ?Could neurobiological markers identify who is most vulnerable to cannabis-related psychosis?
  • ?What role does THC potency play in these neurobiological differences?

Trust & Context

Key Stat:
70 studies with over 3,000 patients reviewed, finding evidence for distinct neurobiological patterns in cannabis-using versus non-using psychosis patients.
Evidence Grade:
Strong - large systematic review of 70 studies with over 3,000 patients, though individual study quality varied.
Study Age:
Published in 2018.
Original Title:
Are cannabis-using and non-using patients different groups? Towards understanding the neurobiology of cannabis use in psychotic disorders.
Published In:
Journal of psychopharmacology (Oxford, England), 32(8), 825-849 (2018)
Database ID:
RTHC-01821

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Analyzes all available research on a topic using a structured method.

What do these levels mean? →

Frequently Asked Questions

Does cannabis change the brain differently in people with psychosis?

This systematic review of 70 studies found evidence that cannabis-using psychosis patients have distinct neurocognitive and neurodevelopmental patterns compared to non-using patients, suggesting cannabis may affect the brain differently in this population.

Does cannabis make psychosis worse?

The evidence reviewed shows cannabis use is associated with increased risk of developing psychosis, more hospitalizations, longer stays, and poorer response to antipsychotic medications.

Read More on RethinkTHC

Cite This Study

RTHC-01821·https://rethinkthc.com/research/RTHC-01821

APA

Sami, Musa Basseer; Bhattacharyya, Sagnik. (2018). Are cannabis-using and non-using patients different groups? Towards understanding the neurobiology of cannabis use in psychotic disorders.. Journal of psychopharmacology (Oxford, England), 32(8), 825-849. https://doi.org/10.1177/0269881118760662

MLA

Sami, Musa Basseer, et al. "Are cannabis-using and non-using patients different groups? Towards understanding the neurobiology of cannabis use in psychotic disorders.." Journal of psychopharmacology (Oxford, 2018. https://doi.org/10.1177/0269881118760662

RethinkTHC

RethinkTHC Research Database. "Are cannabis-using and non-using patients different groups? ..." RTHC-01821. Retrieved from https://rethinkthc.com/research/sami-2018-are-cannabisusing-and-nonusing

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.