Development of an anxiety disorder following an emergency department visit due to cannabis use: a population-based cohort study
Interpretation: ED visits for cannabis use were associated with an increased risk of having an incident healthcare visit for an anxiety disorder, particularly in young males. These findings have important clinical and policy implications given the increasing use of cannabis over time and trend towards legalization of cannabis. (The Lancet)
Nearly a third of people who visited the emergency room for a cannabis-related concern developed a new anxiety disorder within three years, according to research released Monday.
The study—published today in The Lancet’s open access journal eClinical Medicine—is said to be the most comprehensive examination of the relationship between cannabis use and anxiety to date.
Canadian researchers examined the health records of more than 12 million people living in Ontario between 2008 and 2019 who had no record of an anxiety disorder, or of receiving treatment for one. Those who had an emergency room visit for cannabis use during that period were more than three times more likely to be diagnosed with a new anxiety disorder—at an outpatient visit, emergency room, or hospital—within three years, the study found. They were also nine times more likely to require another health care visit—an outpatient or ER visit, or a hospitalization—for an anxiety disorder down the road.
Young cannabis users—ages 10-24 and males, in particular—were at particularly elevated risk, researchers noted. (
