About 50% of respondents in a 2017 Canadian cannabis survey claimed that cannabis had a positive effect on anxiety [19]. Despite this claim, much of the research to date suggests otherwise. For example, there is significant evidence for an association between cannabis use, agoraphobia and social anxiety disorder (SAD) [27, 140]; in a nationally representative study, a clear, statistically significant association was observed between daily cannabis use and SAD [50]. However, findings on this co-morbidity across disorders of anxiety remain mixed. For instance, regarding generalized anxiety disorder (GAD), research ranges from a two-fold increased risk of anxiety symptoms with cannabis use to no significant association between the two factors [37, 144]. One study supports the relationship between cannabis use and GAD, but not between cannabis use and SAD, further complicating the results [66], while others describe persistent reports of heightened anxiety symptoms in cannabis users compared to non-users [42]. Some studies have investigated the effects of cannabis use in early childhood and adolescent stages, demonstrating an increased risk of developing anxiety symptoms and anxiety disorder, which was strengthened with earlier
