Psychotic disorder and cannabis use: Canadian hospitalization trends, 2006–2015

Abstract

Introduction Given the recent and impending changes to the legal status of nonmedical cannabis use in Canada, understanding the effects of cannabis use on the health care system is important for evaluating the impact of policy change. The aim of this study was to examine pre-legalization trends in hospitalizations for mental and behavioural disorders due to the use of cannabis, according to demographics factors and clinical conditions. Methods We assessed the total number of inpatient hospitalizations for psychiatric conditions with a primary diagnosis of a mental or behavioural disorder due to cannabis use (ICD-10-CA code F12) from the Hospital Mental Health Database for ten years spanning 2006 to 2015, inclusive. We included hospitalizations from all provinces and territories except Quebec. Rates (per 100 000 persons) and relative proportions of hospitalizations by clinical condition, age group, sex and year are reported. Results Between 2006 and 2015, the rate of cannabis-related hospitalizations in Canada doubled. Of special note, however, is that hospitalizations during this time period for those with the clinical condition code "mental and behavioural disorders due to use of cannabinoids, psychotic disorder" (F12.5) tripled, accounting for almost half (48%) of all cannabis-related hospitalizations in 2015. Conclusion Further research is required to investigate the reasons for the increase in hospitalizations for cannabis-related psychotic disorder. The introduction of high-potency cannabinoid products and synthetic cannabinoids into the illicit market are considered as possible factors.

A Nationwide Study of Inpatient Case Rate Incidence of Cannabis-Related Diagnoses in Switzerland

“…In relation to cannabis-related psychotic disorder, we found a similar increase to the German cohort of absolute frequencies over the study period. This trend of increased hospitalizations due to CRD was also found in a study cohort in Canada that showed a significant increase in hospitalizations for cannabis-related psychotic disorders [13].…”

Associations Between Canada's Cannabis Legalization and Emergency Department Presentations for Transient Cannabis-Induced Psychosis and Schizophrenia Conditions: Ontario and Alberta, 2015–2019

“…Similarly, national Canadian rates of inpatient hospitalizations with cannabis-induced psychotic conditions (ICD-10 F12.5) tripled from 2006 to 2016, increasing from 0.80 to 2.49 per 100,000 in the Canadian population. 44 Prior international registry-based studies have found similar patterns: a recent study of all inpatient hospital psychiatric admissions in Denmark estimated that the admission rate for cannabis-induced psychosis approximately doubled from 2006 to 2016. 21 The authors 21 speculated that this increasing trend in cannabis-induced psychosis hospitalizations was associated with the parallel increases in the THC content of cannabis products in Denmark [(e.g., the THC potency of cannabis resin in Denmark increased from 13% THC in 2006 to 30% THC in 2016) 45 ].…”

Problematic substance use or problematic substance use policies?

“…Several articles in this special issue contribute toward providing baseline knowledgeofcannabispoisoningand/orinjury harmsovertheyearsleadinguptolegalization. Maloney-Hall et al 2 found that ratesofhospital-basedcannabisusedisorders more than doubled from 2006 to 2015. Champagne et al 3 found increases in cannabis-related poisonings and injuries in the lead up to legalization among bothadultsandyouth,whileChengetal.…”

“…14 With growing evidence for effective policies to reducepopulationalcoholconsumption,it wouldbetimelytoapplylessonslearned from alcohol policy to our other legal drugs.Inthisissue,threepapersfocuson trendsinand/orlevelsofcannabis-related harmsastrackedinCanadiansurveillance systems. Maloney-Hall et al 2 show that between2006and2015,ratesofcannabisrelated hospitalizations doubled. Almost half of these were identified as "mental and behavioural disorders" including "psychotic disorders," which tripled in number.…”