Cannabis use was the strongest predictor of relapse in first-episode schizophrenia over three years
Among 119 patients in remission after a first episode of schizophrenia, 49.6% relapsed within three years, and cannabis use was the factor most strongly associated with relapse (93.2% of relapsers used cannabis vs. 56.7% who stayed in remission).
Quick Facts
What This Study Found
Cannabis consumption was dramatically higher among those who relapsed (93.2%) compared to those who maintained remission (56.7%, p<0.001). Other relapse-associated factors included higher antipsychotic doses, polypharmacy, benzodiazepine use, and side effects. Notably, 22% of those who remained in remission were not taking any antipsychotic.
Key Numbers
119 patients followed; 49.6% relapsed within 3 years. Cannabis use: 93.2% in relapsers vs. 56.7% in remitters (p<0.001). Antipsychotic doses: 381.93 vs. 242.29 mg chlorpromazine equivalents/day (p=0.028). 22% of non-relapsers were off antipsychotics.
How They Did This
Naturalistic longitudinal study following 119 patients in remission after first-episode schizophrenia across 15 tertiary centers in Spain over three years. Sociodemographic, clinical, treatment, and substance use data analyzed.
Why This Research Matters
The strength of the association between cannabis use and relapse in first-episode schizophrenia underscores cannabis cessation as a potentially modifiable target for preventing second episodes.
The Bigger Picture
The finding that cannabis use outperformed all other measured variables in distinguishing relapsers from non-relapsers adds to the growing body of evidence that cannabis is a critical factor in early psychosis outcomes.
What This Study Doesn't Tell Us
Observational design cannot prove cannabis caused relapse. Higher antipsychotic doses and polytherapy in relapsers may reflect more severe illness. Cannabis use was self-reported. No data on cannabis potency or frequency.
Questions This Raises
- ?Would targeted cannabis cessation programs reduce relapse rates?
- ?Does the type or potency of cannabis matter?
- ?Why were some patients stable without antipsychotics while others relapsed despite treatment?
Trust & Context
- Key Stat:
- 93% of relapsers used cannabis vs. 57% of non-relapsers
- Evidence Grade:
- Multi-center longitudinal cohort with 3-year follow-up, but observational design limits causal inference.
- Study Age:
- Published in 2022.
- Original Title:
- Clinical and treatment predictors of relapse during a three-year follow-up of a cohort of first episodes of schizophrenia.
- Published In:
- Schizophrenia research, 243, 32-42 (2022)
- Authors:
- Bioque, Miquel(3), Mezquida, Gisela(6), Amoretti, Sílvia, García-Rizo, Clemente, López-Ilundain, Jose M, Diaz-Caneja, Covadonga M, Zorrilla, Iñaki, Mané, Anna, Rodriguez-Jimenez, Roberto, Corripio, Iluminada, Pomarol-Clotet, Edith, Ibáñez, Ángela, Usall, Judith, Contreras, Fernando, Mas, Sergi, Vázquez-Bourgon, Javier, Cuesta, Manuel J, Parellada, Mara, González-Pinto, Ana, Hidalgo-Figueroa, María, Bernardo, Miquel
- Database ID:
- RTHC-03714
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
How common is relapse after a first episode of schizophrenia?
In this study, nearly half (49.6%) of patients who initially achieved remission relapsed within three years, highlighting the vulnerability of this early period.
Was cannabis the only factor linked to relapse?
No, but it was the most strongly associated factor. Relapsers also had higher antipsychotic doses, more polypharmacy, more benzodiazepine use, and more reported side effects, though these may reflect more severe illness rather than causes of relapse.
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Cite This Study
https://rethinkthc.com/research/RTHC-03714APA
Bioque, Miquel; Mezquida, Gisela; Amoretti, Sílvia; García-Rizo, Clemente; López-Ilundain, Jose M; Diaz-Caneja, Covadonga M; Zorrilla, Iñaki; Mané, Anna; Rodriguez-Jimenez, Roberto; Corripio, Iluminada; Pomarol-Clotet, Edith; Ibáñez, Ángela; Usall, Judith; Contreras, Fernando; Mas, Sergi; Vázquez-Bourgon, Javier; Cuesta, Manuel J; Parellada, Mara; González-Pinto, Ana; Hidalgo-Figueroa, María; Bernardo, Miquel. (2022). Clinical and treatment predictors of relapse during a three-year follow-up of a cohort of first episodes of schizophrenia.. Schizophrenia research, 243, 32-42. https://doi.org/10.1016/j.schres.2022.02.026
MLA
Bioque, Miquel, et al. "Clinical and treatment predictors of relapse during a three-year follow-up of a cohort of first episodes of schizophrenia.." Schizophrenia research, 2022. https://doi.org/10.1016/j.schres.2022.02.026
RethinkTHC
RethinkTHC Research Database. "Clinical and treatment predictors of relapse during a three-..." RTHC-03714. Retrieved from https://rethinkthc.com/research/bioque-2022-clinical-and-treatment-predictors
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.