Why people first tried cannabis was linked to later use patterns and psychosis risk
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.
Quick Facts
What This Study 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.
Key Numbers
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 They Did This
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.
Why This Research 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 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.
What This Study Doesn't 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.
Questions This Raises
- ?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?
Trust & Context
- Key Stat:
- 1,125 participants across 11 European sites; coping-motivated use linked to higher psychosis risk
- Evidence Grade:
- Well-powered multi-site case-control study with path analysis. Retrospective design and recall bias are significant limitations.
- Study Age:
- Published 2022.
- Original Title:
- The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study.
- Published In:
- Psychological medicine, 53(15), 7418-7427 (2023)
- Authors:
- Spinazzola, Edoardo(11), Quattrone, Diego(18), Rodriguez, Victoria(9), 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
- Database ID:
- RTHC-04956
Evidence Hierarchy
Compares people with a condition to similar people without it.
What do these levels mean? →Frequently Asked Questions
Does why you start using cannabis matter for psychosis risk?
According to this study, yes. People who first tried cannabis to cope with negative emotions had higher odds of developing psychosis compared to those who started because friends were using it. The initial motivation also predicted patterns of heavier, more frequent use over time.
What is the EU-GEI study?
The European Gene-Environment Interaction study is a large multi-site research project examining how genes and environmental factors, including cannabis use, interact to influence psychosis risk. It collected data from 11 sites across Europe.
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Cite This Study
https://rethinkthc.com/research/RTHC-04956APA
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
MLA
Spinazzola, Edoardo, et al. "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, 2023. https://doi.org/10.1017/S0033291723001071
RethinkTHC
RethinkTHC Research Database. "The association between reasons for first using cannabis, la..." RTHC-04956. Retrieved from https://rethinkthc.com/research/spinazzola-2023-the-association-between-reasons
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.