Cannabis Use and Cannabis Use Disorder among U.S. Adults with Psychiatric Disorders: 2001-2002 and 2012-2013

Abstract

Objective: Rates of cannabis use disorder (CUD) have increased disproportionately among Veterans Health Administration (VHA) patients with psychiatric disorders, but determining whether such an increase occurred more generally among U.S. adults requires nationally representative data. Methods: Data came from 2001-2002 (n=43,093) and 2012-2013 (n=36,309) national surveys. Outcomes were any past-year non-medical cannabis use, frequent non-medical use (≥3 times weekly), and DSM-IV CUD. Psychiatric disorders included mood, anxiety disorders, antisocial personality disorder, and bipolar I. Logistic regressions were used to generate predicted marginal prevalences of the outcomes for each survey, risk differences calculated, and additive interaction tests determined whether between-survey differences in risk of cannabis outcomes differed between those with and without psychiatric conditions. Results: Cannabis outcome prevalences increased more among those with than without any psychiatric disorder. The difference in prevalence differences included any past-year non-medical cannabis use, 2.45% (95%CI=1.29, 3.62); frequent non-medical cannabis use, 1.58% (95%CI=0.83, 2.33); CUD, 1.40% (95%CI=0.58, 2.21). For each specific disorder, prevalences increased more among those with the disorder, except CUD among those with antisocial personality disorder. Conclusions: In the U.S. general population, rates of cannabis use and CUD increased at a greater rate among adults with psychiatric disorders, similar to findings from VHA patients. These results suggest that although VHA patients are not representative of all U.S. adults, findings from this important patient group can be informative. As U.S. cannabis use continues to expand, greater clinical and policy attention to CUD is needed for adults with psychiatric disorders.