Alcohol and marijuana co-use among adults with chronic low back pain: Associations with substance misuse, mental health, and pain experience

Background and Objectives: Individuals with chronic lower back pain (CLBP) report using alcohol and marijuana to cope with pain. Little research has tested whether co-use is associated with worse psychological outcomes. Methods: Participants had CLBP and past-month alcohol/marijuana co-use (n = 192), alcohol use (n = 148), marijuana use (n = 78), or no use (n = 101). Results: Co-use was associated with more drinking-related problems, anxiety, and pain anxiety compared to alcohol-(but not marijuana-) only, whereas marijuana-only use was associated with worse psychological outcomes than alcohol use-only; effect sizes were small to medium. Discussion and Conclusions: Co-use and marijuana-only were associated with worse outcomes than alcohol-only. Scientific Significance: The present findings extend current understanding of co-use by finding that marijuana use among people with CLBP (a group with especially high rates of use of these substances) is associated with worse alcohol-related problems and psychological outcomes.