Risks Associated with Mid level Cannabis Use Among People Treated for Alcohol Use Disorder.

Background: The relationships between cannabis use frequency with alcohol use, alcohol‐related harms, and persistent alcohol use disorder (AUD) in a general population subsample of individuals previously treated for AUD were examined. Methods: Secondary analyses of the 2005, 2010, and 2015 U.S. National Alcohol Surveys, a nationwide general population sample of individuals ages 18+, were performed. The analytic subsample (N = 772) reported 3+ lifetime DSM‐IV alcohol dependence criteria and prior AUD treatment. Primary exposure was past 12‐month frequency of cannabis use (weekly or more, or "heavy;" more than monthly/less than weekly or "midlevel;" less than monthly or "light;" none). Primary outcomes were past 12‐month total volume, average frequency of 5+ drinks/month, past 12‐month alcohol‐related harms, and past 12‐month DSM‐IV alcohol dependence. Results: Multivariable negative binomial and logistic regressions showed that the only cannabis users who consistently differed significantly from cannabis abstainers were midlevel users; specifically, more than monthly/less than weekly cannabis users drank 2.83 times as many drinks (95% CI: 1.43, 5.60); had 2.83 as many 5+ occasions (95% CI: 1.38, 5.79); had 6.82 times the odds of experiencing any harms (95% CI: 2.29, 20.33); and had 6.53 times the odds of persistent AUD as cannabis abstainers (95% CI: 2.66, 16.02; all ps < 0.05). The relationship between midlevel cannabis use and harms remained significant after adjustment for volume and frequency of 5+ (OR = 6.18, 95% CI: 1.35, 28.37). Conclusions: Among those with lifetime AUD who have been to treatment, only more than monthly/less than weekly cannabis use is related to more alcohol‐related harms and persistent AUD compared to cannabis abstinence. Heavier and lighter cannabis use is not related to worse alcohol outcomes compared to cannabis abstinence. Among individuals previously treated for alcohol use disorder (AUD), those who use cannabis more than monthly/less than weekly had 2.83 times the number drinks, 2.83 times more heavy drinking episodes, 6.53 times greater odds of current alcohol dependence, and 6.82 times higher odds of alcohol‐related harms in the past 12 months compared to cannabis abstainers. Those who use cannabis weekly or more did not differ from cannabis abstainers on any of these outcomes. [ABSTRACT FROM AUTHOR]