The ARCH Lab recently contributed to a paper titled “How High? Trends in Cannabis Use Prior to First Admission to Inpatient Psychiatry in Ontario, Canada, between 2007 and 2017: À quelle hauteur? Les tendances de l’usage du cannabis avant la première hospitalisation en psychiatrie en Ontario, Canada entre 2007 et 2017”. The study aimed to look at the trends in cannabis use within 30 days of first admissions to an inpatient psychiatry unit in Ontario, Canada, between 2007 and 2017 and characteristics of persons use.

Data was obtained using the Ontario Mental Health Reporting System. From 2007-2017 20.1% of patients reported cannabis use within 30 days of first admission with an increase of use from 2007 (16.7%) to 2017 (25.9%).  A range of other clinical and demographic factors were associated with cannabis use, including age and diagnosis.

In recent years, policies around medical cannabis in Canada have evolved and these findings are a good starting point to begin evaluating the impact these changes have had on cannabis use prior to admission to inpatient psychiatry.