Cannabis use and duration of untreated psychosis: a systematic review of clinical predictors and neurobiological correlates
5 affiliations
- 1University of Turin
- 2San Luigi Gonzaga Hospital
- 3Psychiatry Department, Unicamillus International University of Medical Science
- 4Department of Neurosciences, Imaging and Clinical Sciences, Università degli Studi G. D’Annunzio Chieti-Pescara
- 5Department of Neurosciences “Rita Levi Montalcini”, University of Turin
Abstract
Background: Duration of untreated psychosis (DUP) is an established prognostic factor in first-episode psychosis, and cannabis use is highly prevalent in these populations, yet whether and in which direction the two are related remains unclear.
Objective: To review the evidence on cannabis use and DUP in first-episode psychosis, with attention to how exposure and outcome have been defined.
Methods: Five databases were searched for observational studies reporting DUP in relation to cannabis use, either directly or alongside other variables. Quality was appraised with Newcastle-Ottawa Scale, and findings were synthesised narratively.
Results: Twenty-three studies were included, with samples ranging from 33 to 1,266 patients. The direction of the associations varied with the definition of exposure. Among studies assessing current or recent use, one small sample reported a significantly shorter DUP and two pointed in the same direction, whereas the two largest samples reported a longer untreated period and several found no difference. Among studies assessing lifetime use or a cannabis use disorder, none reported a shorter DUP. Both studies examining adolescents reported longer DUP among users, and where cannabis was analysed jointly with social or genetic moderators its association depended on the context of use. Smaller unadjusted samples tended to favour shorter DUP, larger representative ones did not.
Conclusions: The evidence does not support a consistently shorter DUP among cannabis users. The direction of the association appears to depend on how exposure is defined, on age and on setting, and the variability in the operationalisation of DUP further limits comparability.
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BibTeX
@article{ricci2026cannabis,
title = {{Cannabis use and duration of untreated psychosis: a systematic review of clinical predictors and neurobiological correlates}},
author = {Valerio Ricci and Stefania Chiappini and Giovanni Martinotti and Giuseppe Maina},
journal = {Frontiers in Psychiatry},
year = {2026},
month = nov,
doi = {10.3389/fpsyt.2026.1986256},
url = {https://www.frontiersin.org/articles/10.3389/fpsyt.2026.1986256/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Cannabis use and duration of untreated psychosis: a systematic review of clinical predictors and neurobiological correlates
AU - Valerio Ricci
AU - Stefania Chiappini
AU - Giovanni Martinotti
AU - Giuseppe Maina
PY - 2026
DA - 2026/11/02
JO - Frontiers in Psychiatry
DO - 10.3389/fpsyt.2026.1986256
UR - https://www.frontiersin.org/articles/10.3389/fpsyt.2026.1986256/full
AB - Background: Duration of untreated psychosis (DUP) is an established prognostic factor in first-episode psychosis, and cannabis use is highly prevalent in these populations, yet whether and in which direction the two are related remains unclear. Objective: To review the evidence on cannabis use and DUP in first-episode psychosis, with attention to how exposure and outcome have been defined. Methods: Five databases were searched for observational studies reporting DUP in relation to cannabis use, either directly or alongside other variables. Quality was appraised with Newcastle-Ottawa Scale, and findings were synthesised narratively. Results: Twenty-three studies were included, with samples ranging from 33 to 1,266 patients. The direction of the associations varied with the definition of exposure. Among studies assessing current or recent use, one small sample reported a significantly shorter DUP and two pointed in the same direction, whereas the two largest samples reported a longer untreated period and several found no difference. Among studies assessing lifetime use or a cannabis use disorder, none reported a shorter DUP. Both studies examining adolescents reported longer DUP among users, and where cannabis was analysed jointly with social or genetic moderators its association depended on the context of use. Smaller unadjusted samples tended to favour shorter DUP, larger representative ones did not. Conclusions: The evidence does not support a consistently shorter DUP among cannabis users. The direction of the association appears to depend on how exposure is defined, on age and on setting, and the variability in the operationalisation of DUP further limits comparability.
SN - 1664-0640
ER -