People who first used cannabis to cope with negative emotions were more likely to develop problematic use patterns and had higher odds of first-episode psychosis compared to those who started for social reasons.
Psychiatrists, psychosis researchers, prevention specialists, and young adults interested in understanding cannabis risk factors.
1,125 participants across 11 European sites; coping-motivated use linked to higher psychosis risk
What the researchers found
Starting cannabis use "to feel better/cope" was associated with higher odds of first-episode psychosis (FEP) compared to starting "because of friends." Path analysis showed reasons for first use influenced later patterns (frequency, potency, duration) which in turn affected psychosis risk.
Why it matters
Understanding why people start using cannabis may help identify those at higher risk for problematic outcomes. If initial motivations predict later patterns and psychosis risk, early intervention could target people using cannabis to self-medicate.
The numbers in context
558 FEP patients and 567 controls across 11 EU-GEI sites. Most common reason for first use: "because of friends" (86.1% of controls, 75.6% of FEP patients). Using to cope was associated with higher psychosis risk.
How the study worked
Case-control study from the EU-GEI multi-site project. 558 first-episode psychosis patients and 567 population controls who had used cannabis reported their reasons for first use. Logistic regression and path analysis examined associations between initial motivations, use patterns, and psychosis.
What this study cannot tell us
Retrospective recall of reasons for first cannabis use may be unreliable, especially for FEP patients whose memory and cognition may be affected. Case-control design cannot establish temporal causation. Self-medication bias may inflate the coping-psychosis association.
How to read the evidence
Well-powered multi-site case-control study with path analysis. Retrospective design and recall bias are significant limitations.
When this study was published
Published 2022.
The bigger picture
The cannabis-psychosis association is well-established, but not everyone who uses cannabis develops psychosis. Identifying risk modifiers like motivation for use could help move from blanket warnings toward more targeted risk communication.
Questions still open
- Can prospective studies confirm that coping-motivated initiation predicts psychosis risk? Would screening for self-medication motives in young cannabis users improve early identification of at-risk individuals?
Common questions
Does why you start using cannabis matter for psychosis risk?
What is the EU-GEI study?
Read the original research
The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study.
Psychological medicine, 53(15), 7418-7427
Citation
Spinazzola, Edoardo; Quattrone, Diego; Rodriguez, Victoria; Trotta, Giulia; Alameda, Luis; Tripoli, Giada; Gayer-Anderson, Charlotte; Freeman, Tom P; Johnson, Emma C; Jongsma, Hannah E; Stilo, Simona; La Cascia, Caterina; Ferraro, Laura; La Barbera, Daniele; Lasalvia, Antonio; Tosato, Sarah; Tarricone, Ilaria; D'Andrea, Giuseppe; Galatolo, Michela; Tortelli, Andrea; Tagliabue, Ilaria; Turco, Marco; Pompili, Maurizio; Selten, Jean-Paul; de Haan, Lieuwe; Rossi Menezes, Paulo; Del Ben, Cristina M; Santos, Jose Luis; Arrojo, Manuel; Bobes, Julio; Sanjuán, Julio; Bernardo, Miguel; Arango, Celso; Kirkbride, James B; Jones, Peter B; O'Donovan, Michael; Rutten, Bart P; Van Os, Jim; Morgan, Craig; Sham, Pak C; Austin-Zimmerman, Isabelle; Li, Zhikun; Vassos, Evangelos; Murray, Robin M; Di Forti, Marta. (2023). The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study.. Psychological medicine, 53(15), 7418-7427. https://doi.org/10.1017/S0033291723001071
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