Facts & Risks

Key Points
Question Have cannabis-involved traffic injury emergency department visits changed after cannabis legalization and the subsequent commercialization of the cannabis retail market (ie, store and product expansion) in Ontario, Canada?

Findings In this cross-sectional study capturing 426 cannabis-involved traffic injury emergency department visits, annual rates of cannabis involvement increased by 475.3% over 13 years. After accounting for time trends, legalization with restrictions was not associated with increased cannabis involvement during traffic injury emergency department visits; however, market commercialization, which overlapped with the COVID-19 pandemic, was.

Meaning These findings suggest that cannabis-involved traffic injuries have increased over time and that the commercialization of cannabis markets may result in further increases.

Key Points
Question What is the prevalence of cannabis use disorder (CUD) among primary care patients who use cannabis in a state with legal recreational cannabis use, and does prevalence differ by reason for use?

Findings In this cross-sectional study, weighted prevalence of any CUD did not vary by reason for cannabis use, whereas the prevalence of moderate to severe CUD did. Prevalence of moderate to severe CUD was higher in those who reported nonmedical use only or both medical and nonmedical use.

Meaning In this study, CUD was common among patients who use cannabis in a state with legal recreational cannabis use, with moderate to severe CUD most prevalent among patients with any nonmedical use.

Offspring of female nonhuman primates given a cannabis product during pregnancy had changes in their DNA expression like those seen in human children with autism spectrum disorder and attention deficit hyperactivity disorder, according to a small study funded by the National Institutes of Health. The changes involved addition of chemicals known as methyl groups to DNA, which switch genes on or off without changing their structure. The findings suggest that children whose mothers consume edibles or other products containing Delta-9-tetrahydrocannabinol (THC), the main psychoactive substance found in cannabis, could experience permanent developmental changes.

Abstract

Objective: Cannabis use is increasingly normalized; psychosis is a major adverse health outcome. We reviewed evidence on cannabis use-related risk factors for psychosis outcomes at different stages toward recommendations for risk reduction by individuals involved in cannabis use.

Methods: We searched primary databases for pertinent literature/data 2016 onward, principally relying on reviews and high-quality studies which were narratively summarized and quality-graded; recommendations were developed by international expert consensus.

Abstract

The increasing prevalence and burden of suicide have led to numerous studies to identify its risk factors. Cannabis is the most common illicit substance detected in suicide victims’ toxicology tests. This study aims to identify and appraise systematic reviews investigating suicidality after using cannabis and cannabinoids. Seven databases and two registries were searched without restrictions for systematic reviews investigating cannabis effects on suicidality. AMSTAR-2 was used for quality assessment and corrected covered area and citation matrix were used to determine overlap. Twenty-five studies were included, of which 24 were on recreational use and one was on therapeutic use. Only three of the studies on recreational use reported no effect or inconsistent results. Evidence generally showed a positive association between cannabis use and suicidal ideation and attempt among the general population, military veterans, and bipolar or major depression patients. A bidirectional causal association between cannabis and suicidal ideation was also mentioned. Moreover, a younger age of initiation, long-term use, and heavy consumption were reported to be associated with even worse suicidal outcomes. On the contrary, current evidence indicates that the therapeutic cannabis is safe. In conclusion, the literature supports the cannabis-suicidality association in recreational use but considers cannabidiol safe for treatment. Further studies with quantitative and interventional approaches are recommended.