Cannabis use among US adults with anxiety from 2008 to 2017: The role of state-level cannabis legalization

Background: Cannabis use is more common among adults with anxiety. Cannabis legalization is occurring rapidly across the United States (US) and individuals may use cannabis to cope with anxiety. This study investigated whether cannabis use across the US has changed differentially by anxiety status and by state cannabis legalization for medical (MML) and/or recreational use (RML). Methods: Public and restricted-use data from the 2004 to 2017 National Survey on Drug Use and Health, an annual cross-sectional, nationally representative survey of US individuals, were analyzed. The prevalence of past-30-day cannabis use by anxiety status in 2017 was estimated among respondents ages >= 18 (n = 42,554) by sociodemographics and state-level cannabis law. Weighted logistic regressions with continuous year as the predictor for the linear time trend were used to examine the time trends in cannabis use by anxiety and cannabis law status from 2004 to 2017 (total combined analytic sample n = 398,967). Results: Cannabis use was consistently two to three times higher among those with high anxiety compared to those with some or no anxiety and was higher in states with RML compared to MML or no MML/RML. Cannabis use has increased over time among those with and without anxiety overall, in MML states, and in states without MML/RML; with a faster increase in cannabis use among those with high anxiety compared to lower anxiety in states with MML. Conclusions: Cannabis use is increasing among American adults overall, yet is disproportionately common among Americans with anxiety especially among those residing in states where cannabis has been legalized.