Cannabis use worsened disorganized thinking in people at risk for psychosis but did not trigger transition to psychotic disorders

Among people showing early signs of psychosis risk, cannabis use was linked to worse disorganization symptoms but did not increase the rate of transition to full psychotic disorders over 2.5 years.

de Medeiros, Matheus Wanderley et al.·Psychiatry research·2024·Moderate EvidenceObservational
RTHC-05258ObservationalModerate Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Moderate Evidence
Sample
N=109

What This Study Found

In a community sample of 109 at-risk individuals and 197 controls from Sao Paulo, Brazil, cannabis use patterns did not differ between the two groups and did not predict transition to psychiatric disorders. However, among the at-risk group, cannabis use was significantly associated with more severe disorganization symptoms.

Key Numbers

109 at-risk individuals and 197 controls were followed for a mean of 2.5 years. No significant differences in lifetime, current, or maximum cannabis use between groups. Cannabis use significantly correlated with disorganization symptoms in the at-risk group.

How They Did This

Prospective cohort study drawing from the general population (non-help-seeking) with 2.5-year follow-up. Cannabis use was assessed with the South Westminster modified questionnaire. Transition to psychiatric disorders was tracked through reassessment.

Why This Research Matters

Most studies on cannabis and psychosis risk recruit from clinical settings. This study used a community sample of people not seeking help, providing a different perspective on how cannabis affects early psychosis risk in the general population.

The Bigger Picture

The finding that cannabis worsens specific symptom dimensions without accelerating full transition adds nuance to the cannabis-psychosis debate, suggesting the relationship may be more about symptom severity than triggering new disorders.

What This Study Doesn't Tell Us

Relatively small sample size for transition analysis. Self-reported cannabis use. Community-based sample may have milder risk profiles than clinical populations. 2.5-year follow-up may be too short to capture all transitions.

Questions This Raises

  • ?Why does cannabis specifically worsen disorganization rather than other symptom domains?
  • ?Would longer follow-up reveal eventual transitions?

Trust & Context

Key Stat:
109 at-risk individuals followed 2.5 years; no increase in transition to psychosis
Evidence Grade:
Prospective cohort with community sampling, though modest sample size limits transition analysis.
Study Age:
2024 study
Original Title:
Cannabis use influences disorganized symptoms severity but not transition in a cohort of non-help-seeking individuals at-risk for psychosis from São Paulo, Brazil.
Published In:
Psychiatry research, 331, 115665 (2024)
Database ID:
RTHC-05258

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

What are disorganization symptoms?

Disorganization refers to disordered thinking, speech, and behavior, such as jumping between unrelated topics, difficulty organizing thoughts, or behaving in ways that seem random or purposeless.

Does this mean cannabis is safe for people at risk of psychosis?

Not necessarily. Cannabis was associated with worse symptoms even if it did not trigger full transition in this study. The sample was small and follow-up relatively short.

Read More on RethinkTHC

Cite This Study

RTHC-05258·https://rethinkthc.com/research/RTHC-05258

APA

de Medeiros, Matheus Wanderley; Andrade, Julio Cesar; Haddad, Natalia Mansur; Mendonça, Melina; de Jesus, Leonardo Peroni; Fekih-Romdhane, Feten; van de Bilt, Martinus Theodorus; Gattaz, Wagner Farid; Loch, Alexandre Andrade. (2024). Cannabis use influences disorganized symptoms severity but not transition in a cohort of non-help-seeking individuals at-risk for psychosis from São Paulo, Brazil.. Psychiatry research, 331, 115665. https://doi.org/10.1016/j.psychres.2023.115665

MLA

de Medeiros, Matheus Wanderley, et al. "Cannabis use influences disorganized symptoms severity but not transition in a cohort of non-help-seeking individuals at-risk for psychosis from São Paulo, Brazil.." Psychiatry research, 2024. https://doi.org/10.1016/j.psychres.2023.115665

RethinkTHC

RethinkTHC Research Database. "Cannabis use influences disorganized symptoms severity but n..." RTHC-05258. Retrieved from https://rethinkthc.com/research/de-2024-cannabis-use-influences-disorganized

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.