As cannabis legalization has increased throughout the US, so has the hand-wringing about public health. A new survey of the literature on the link between weed use and anxiety, however, has put one concern to rest: Developing an anxiety disorder as the sole result of using cannabis is highly unlikely.
Previous research has indicated that people who use cannabis are at a higher risk for developing anxiety disorder symptoms. Dr. Conal Twomey, a UK-based researcher at the University of Southhampton, set out to interrogate the claim when he realized that many of the studies were flawed. "Randomly in a 'journal club' meeting, I found out that most existing studies on the apparent (and widely publicized) cannabis-anxiety link were cross-sectional in nature," he told Broadly.
This means they only targeted a sample population of stoners. "These studies therefore cannot tell us about the directionality of the cannabis–anxiety association," he explained. "Is cannabis use causing anxiety, or are people with anxiety more likely to use cannabis due to the reported stress-relieving functions of the drug?"
When Twomey analyzed 10 longitudinal, general population studies—which in total included just under 60,000 subjects—and controlled "for a range of potential confounders including demographics, mental health problems, and substance abuse," he found that the link between using cannabis and developing anxiety disorder symptoms is very weak.
"The odds of developing elevated anxiety symptoms were 1.15 times higher for more frequent cannabis users than less frequent or non-users," he said. "This is a significant yet very small odds ratio."
Further, when he confined his analysis to "high quality" studies within his sample set, he found that the link between cannabis use and anxiety disorder symptoms is not significant. There was also no significant link between cannabis use and being diagnosed with an anxiety disorder. "When study quality was taken into account, the odds ratio dropped to a non-significant level (1.04)," Twomey said. "So I conclude that cannabis use is—at worst—a minor risk factor for the development of anxiety for the average person in the general population."
Knowing that I will be heavily smoking weed to make it through the next four years, I'll take those odds.