Cannabis-related schizophrenia may require less medication but leads to more hospitalizations
In a nationwide Danish study of over 35,000 people with schizophrenia, those whose psychosis was preceded by cannabis use disorder used less antipsychotic medication but had more psychiatric hospitalizations.
Quick Facts
What This Study Found
Among 35,714 people with incident schizophrenia (11.5% cannabis-related), propensity-score matched analysis showed cannabis-related cases used significantly less antipsychotics and benzodiazepines. In unmatched analysis, the cannabis-related group had more days admitted, though this was markedly attenuated after matching.
Key Numbers
35,714 people with incident schizophrenia; 4,116 (11.5%) cannabis-related; lower antipsychotic and benzodiazepine use after propensity matching; more hospitalization days in unmatched analysis, attenuated after matching
How They Did This
Nationwide Danish registry study identifying all individuals with incident schizophrenia from 1995 to 2016. Cannabis-related schizophrenia was defined by a cannabis use disorder diagnosis preceding schizophrenia. Cases were compared to both all non-cannabis-related patients and propensity-score matched controls.
Why This Research Matters
If cannabis-related schizophrenia responds differently to treatment, it could have implications for how clinicians approach medication decisions and hospital planning for this subgroup.
The Bigger Picture
The finding that cannabis-related schizophrenia may represent a distinct clinical entity supports growing interest in understanding whether the route to psychosis matters for treatment and prognosis.
What This Study Doesn't Tell Us
Registry data cannot determine if differences reflect distinct biology or behavioral patterns like treatment non-adherence; cannabis use disorder diagnosis may not capture all cannabis-related cases; propensity matching cannot account for unmeasured confounders
Questions This Raises
- ?Is the lower medication use a sign that cannabis-related schizophrenia is a milder subtype, or does it reflect reduced treatment adherence?
- ?Would cannabis cessation improve outcomes in this subgroup?
Trust & Context
- Key Stat:
- 35,714 schizophrenia patients, 11.5% cannabis-related
- Evidence Grade:
- Large nationwide registry study with propensity-score matching, though limited by inability to distinguish biological from behavioral explanations.
- Study Age:
- 2024 publication analyzing 1995-2016 data
- Original Title:
- Use of antipsychotic medication, benzodiazepines, and psychiatric hospitalization in cannabis-related versus cannabis-unrelated schizophrenia - a nationwide, register-based cohort study.
- Published In:
- Psychological medicine, 54(10), 2634-2643 (2024)
- Authors:
- Hjorthøj, Carsten(11), Stürup, Anne, Karlsen, Mette, Speyer, Helene, Osler, Merete, Ongur, Dost, Nordentoft, Merete
- Database ID:
- RTHC-05379
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
How did cannabis-related schizophrenia differ from other cases?
After propensity-score matching to account for other differences between groups, people whose schizophrenia was preceded by cannabis use disorder used significantly less antipsychotic medication and benzodiazepines. The initial finding of more hospitalization days was largely explained by other factors once matching was applied.
Does this mean cannabis causes a different type of schizophrenia?
The researchers suggest cannabis-related schizophrenia may be a distinct disorder in terms of prognosis, but they cannot determine whether the differences stem from different underlying biology or from behavioral factors like reduced treatment-seeking among cannabis users.
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Cite This Study
https://rethinkthc.com/research/RTHC-05379APA
Hjorthøj, Carsten; Stürup, Anne; Karlsen, Mette; Speyer, Helene; Osler, Merete; Ongur, Dost; Nordentoft, Merete. (2024). Use of antipsychotic medication, benzodiazepines, and psychiatric hospitalization in cannabis-related versus cannabis-unrelated schizophrenia - a nationwide, register-based cohort study.. Psychological medicine, 54(10), 2634-2643. https://doi.org/10.1017/S0033291724000758
MLA
Hjorthøj, Carsten, et al. "Use of antipsychotic medication, benzodiazepines, and psychiatric hospitalization in cannabis-related versus cannabis-unrelated schizophrenia - a nationwide, register-based cohort study.." Psychological medicine, 2024. https://doi.org/10.1017/S0033291724000758
RethinkTHC
RethinkTHC Research Database. "Use of antipsychotic medication, benzodiazepines, and psychi..." RTHC-05379. Retrieved from https://rethinkthc.com/research/hjorthoj-2024-use-of-antipsychotic-medication
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.