@article{ref1,
title="Risk-thresholds for the association between frequency of cannabis use and the development of psychosis: a systematic review and meta-analysis",
journal="Psychological medicine",
year="2022",
author="Robinson, Tessa and Ali, Muhammad Usman and Easterbrook, Bethany and Hall, Wayne and Jutras-Aswad, Didier and Fischer, Benedikt",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="BACKGROUND: Epidemiological studies show a dose-response association between cannabis use and the risk of psychosis. This review aimed to determine whether there are identifiable risk-thresholds between the frequency of cannabis use and psychosis development. <br><br>METHODS: Systematic search of Embase, MEDLINE, PsycINFO, CINAHL, and Web of Science for relevant studies (1 January 2010-26 April 2021). Case-control or cohort studies that investigated the relationship between cannabis use and the risk of psychosis development that reported effect estimates [odds ratios (OR), hazard ratios (HR), risk ratios (RR)] or the raw data to calculate them, with information on the frequency of cannabis consumption were included. Effect estimates were extracted from individual studies and converted to RR. Two-stage dose-response multivariable meta-analytic models were utilized and sensitivity analyses conducted. The Newcastle Ottawa Scale was used to assess the risk of bias of included studies. <br><br>RESULTS: Ten original (three cohorts, seven case-control) studies were included, including 7390 participants with an age range of 12-65 years. Random-effect model meta-analyses showed a significant log-linear dose-response association between cannabis use frequency and psychosis development. A restricted cubic-splines model provided the best fit for the data, with the risk of psychosis significantly increasing for weekly or more frequent cannabis use [RR = 1.01, 95% confidence interval (CI) 0.93-1.11 yearly; RR = 1.10, 95% CI 0.97-1.25 monthly; RR = 1.35, 95% CI 1.19-1.52 weekly; RR = 1.76, 95% CI 1.47-2.12 daily]. <br><br>CONCLUSION: Individuals using cannabis frequently are at increased risk of psychosis, with no significant risk associated with less frequent use. Public health prevention messages should convey these risk-thresholds, which should be refined through further work.<p /> <p>Language: en</p>",
language="en",
issn="0033-2917",
doi="10.1017/S0033291722000502",
url="http://dx.doi.org/10.1017/S0033291722000502"
}