Trends in Cannabis Use Prior to First Admission to Inpatient Psychiatry in Ontario, Canada, Between 2007 and 2017 (Report at a Glance)

Highlights the correlation between cannabis use and admission to inpatient psychiatry beds in Ontario between 2007 and 2017. The study shows that prior cannabis use was common among people at first admission to inpatient psychiatry. It suggests that trends in use among vulnerable groups, such as those with mental illness, need to be monitored to evaluate the effect of cannabis-related policies on different cohorts of psychiatric inpatients.

Key points include:

• Prior cannabis use has become more common among individuals at first admission to inpatient psychiatric beds in Ontario.
• Young adults (ages 18 to 24 years) were more likely to use cannabis before their first admission to inpatient psychiatry than older adults (ages 55 years and older).
• Cannabis use increased more in males than females between 2007 and 2017. Males with schizophrenia were more likely to use cannabis but females with schizophrenia were less likely to use cannabis.
• Having a mood disorder or experiencing mania or psychotic symptoms were strongly associated with cannabis use.
• Using tobacco and alcohol were strongly associated with cannabis use