Cannabis Users With Psychosis Show Fewer Cognitive Biases Than Non-Users
In the EU-GEI study of 1,914 participants, cannabis use was associated with fewer cognitive biases compared to never-use, while low-potency cannabis was paradoxically associated with more cognitive biases than high-potency cannabis.
Quick Facts
What This Study Found
Daily and occasional cannabis use were associated with lower odds of speech illusions (OR = 0.605 and 0.646) and jumping to conclusions bias (OR = 0.625 and 0.602) compared to never-use. Low-potency use was associated with higher odds of all three cognitive biases compared to high-potency use.
Key Numbers
1,914 participants; daily use OR 0.605 for speech illusions; occasional use OR 0.602 for JTC; low vs high potency: OR 1.829 for SI, 1.393 for FRP, 1.661 for JTC.
How They Did This
Cross-sectional analysis of 543 first-episode psychosis patients, 203 siblings, and 1,168 controls from the EU-GEI multi-site study.
Why This Research Matters
The counterintuitive finding that cannabis users show fewer cognitive biases challenges simple narratives about cannabis and cognition in psychosis.
The Bigger Picture
These findings complicate the cannabis-psychosis narrative and raise questions about self-selection and the role of the endocannabinoid system in cognitive processing.
What This Study Doesn't Tell Us
Cross-sectional design prevents causal inference. Self-reported cannabis potency.
Questions This Raises
- ?Why would cannabis users show fewer cognitive biases than non-users?
- ?Is the low-potency finding a real effect or artifact of who chooses low-potency products?
Trust & Context
- Key Stat:
- Cannabis users had 40% lower odds of jumping-to-conclusions bias
- Evidence Grade:
- Large multi-site study with appropriate controls, limited by cross-sectional design and self-reported potency.
- Study Age:
- 2024 publication
- Original Title:
- Cannabis use and cognitive biases in people with first-episode psychosis and their siblings.
- Published In:
- Psychological medicine, 54(15), 1-11 (2024)
- Authors:
- Roldan, L, Sánchez-Gutiérrez, T, Fernández-Arias, I, Rodríguez-Toscano, E, López, G, Merchán-Naranjo, J, Calvo, A, Rapado-Castro, M, Parellada, M, Moreno, C, Ferraro, L, La Barbera, D, La Cascia, C, Tripoli, G, Di Forti, M, Murray, R M, Quattrone, D, Morgan, C, Gayer-Anderson, C, Jones, P B, Jongsma, H E, Kirkbride, J B, van Os, J, García-Portilla, P, Al-Halabí, S, Bobes, J, de Haan, L, Bernardo, M, Santos, J L, Sanjuán, J, Arrojo, M, Szoke, A, Rutten, B P, Stilo, S A, Tarricone, I, Lasalvia, A, Tosato, S, Llorca, P-M, Menezes, P Rossi, Selten, J-P, Tortelli, A, Velthorst, E, Del-Ben, C M, Arango, C, Díaz-Caneja, C M
- Database ID:
- RTHC-05661
Evidence Hierarchy
Frequently Asked Questions
Does cannabis affect cognitive biases in psychosis?
Surprisingly, cannabis users (including those with psychosis) had fewer cognitive biases like jumping to conclusions and speech illusions compared to non-users.
Does cannabis potency matter for cognitive effects?
Counterintuitively, low-potency cannabis users showed more cognitive biases than high-potency users. This may reflect who chooses different potency products rather than a direct pharmacological effect.
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Cite This Study
https://rethinkthc.com/research/RTHC-05661APA
Roldan, L; Sánchez-Gutiérrez, T; Fernández-Arias, I; Rodríguez-Toscano, E; López, G; Merchán-Naranjo, J; Calvo, A; Rapado-Castro, M; Parellada, M; Moreno, C; Ferraro, L; La Barbera, D; La Cascia, C; Tripoli, G; Di Forti, M; Murray, R M; Quattrone, D; Morgan, C; Gayer-Anderson, C; Jones, P B; Jongsma, H E; Kirkbride, J B; van Os, J; García-Portilla, P; Al-Halabí, S; Bobes, J; de Haan, L; Bernardo, M; Santos, J L; Sanjuán, J; Arrojo, M; Szoke, A; Rutten, B P; Stilo, S A; Tarricone, I; Lasalvia, A; Tosato, S; Llorca, P-M; Menezes, P Rossi; Selten, J-P; Tortelli, A; Velthorst, E; Del-Ben, C M; Arango, C; Díaz-Caneja, C M. (2024). Cannabis use and cognitive biases in people with first-episode psychosis and their siblings.. Psychological medicine, 54(15), 1-11. https://doi.org/10.1017/S0033291724001715
MLA
Roldan, L, et al. "Cannabis use and cognitive biases in people with first-episode psychosis and their siblings.." Psychological medicine, 2024. https://doi.org/10.1017/S0033291724001715
RethinkTHC
RethinkTHC Research Database. "Cannabis use and cognitive biases in people with first-episo..." RTHC-05661. Retrieved from https://rethinkthc.com/research/roldan-2024-cannabis-use-and-cognitive
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.