Medical Observer: September 11, 2012

A longitudinal study by researchers at the National Drug and Alcohol Research Centre, UNSW, has found that “teenagers who used cannabis weekly or more were twice as likely as non-users to have an anxiety disorder in their late 20s, even if they had stopped using the drug years earlier.” Further, “the strong association held even a decade after the drug use had ceased, even after adjusting for factors such as other mental health issues or other drug use in their 20s.” Those who used cannabis frequently in their teenage years and continued to use during their 20s had “triple the risk of an anxiety disorder compared with those who used only infrequently or not at all.” Despite the findings, the authors “acknowledge there is no proof yet of causation – for example they can’t rule out the possibility that the same predisposing factors that would make someone more prone to an anxiety disorder, might also predispose them to smoking cannabis at a younger age.” However the researchers still believe that “it’s plausible that cannabis plays a role in the development of anxiety disorders, and further research is warranted.”