In 33 first-episode psychosis patients, cannabis use history was a significant predictor of longer duration of untreated psychosis in a multivariate model that also included age and negative symptoms.
Early psychosis intervention programs, psychiatrists, and cannabis-using individuals with psychotic symptoms.
Cannabis use predicted longer duration of untreated psychosis
What the researchers found
No single sociodemographic or disease factor predicted duration of untreated psychosis (DUP) individually except education level. In multivariate analysis, age at inclusion, negative symptoms, and cannabis use history significantly predicted longer DUP.
Why it matters
Longer DUP is associated with worse long-term outcomes in psychosis. If cannabis use contributes to delayed treatment-seeking, this is a modifiable factor that early intervention programs should address.
The numbers in context
33 patients studied. Cannabis use, age, and negative symptoms were significant predictors of DUP in multivariate analysis. No other individual factors were significant.
How the study worked
Prospective study of 33 consecutive patients crossing the CAARMS psychosis threshold at a specialized early detection clinic in Paris. DUP and cannabis history assessed through comprehensive interviews of patients, parents, and practitioners.
What this study cannot tell us
Very small sample (n=33). Single-center study in Paris. DUP measurement depends on accurate recall of symptom onset. Multivariate model with three predictors in 33 subjects has limited statistical power.
How to read the evidence
Preliminary: small prospective study (n=33) from a single site.
When this study was published
Published in 2019.
The bigger picture
Cannabis users with emerging psychosis may be less likely to seek help, possibly because cannabis provides perceived symptom relief, reduces insight into illness, or exists in a social context where help-seeking is less likely.
Questions still open
- Does cannabis reduce insight into psychotic symptoms? Would cannabis-focused outreach reduce DUP? Are cannabis-using patients referred to treatment through different pathways than non-users?
Common questions
What is duration of untreated psychosis?
Why might cannabis users delay treatment?
Read the original research
Individual factors influencing the duration of untreated psychosis.
Early intervention in psychiatry, 13(4), 798-804
Citation
Souaiby, Lama; Gauthier, Claire; Kazes, Mathilde; Mam-Lam-Fook, Célia; Daban, Claire; Plaze, Marion; Gaillard, Raphaël; Krebs, Marie-Odile. (2019). Individual factors influencing the duration of untreated psychosis.. Early intervention in psychiatry, 13(4), 798-804. https://doi.org/10.1111/eip.12562
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