The bidirectional relationships between alcohol, cannabis, co-occurring alcohol and cannabis use disorders with major depressive disorder: Results from a national sample

IntroductionAlcohol use disorders (AUD) and cannabis use disorders (CUD) are common in the United States (US), and are associated with major depressive disorder (MDD). Co-occurring alcohol and cannabis use/use disorders (AUD+CUD), though understudied, have been found to be associated with greater adverse outcomes than alcohol or cannabis use/use disorders alone. There is a paucity of research on the co-occurring relationships of the two disorders with depression.MethodsData came from Waves 1 and 2 of the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC), a population-based longitudinal survey of the adult non-institutionalized, civilian population in the US. Logistic regression analyses were used to assess the associations between: 1) baseline AUD, CUD, and co-occurring AUD+CUD with incident MDD at follow-up and 2) baseline MDD with incident AUD, CUD, and co-occurring AUD+CUD at follow-up, adjusted for potential confounding variables.ResultsFor Aim 1, most of the AUD and CUD were positively associated with MDD. The strongest associations with incident MDD were observed for cannabis dependence (OR=6.61, CI=1.67-26.21) and co-occurring alcohol and cannabis dependence (OR=2.34, CI=1.23-4.48). For Aim 2, baseline MDD was significantly associated with comparatively fewer cases of incident AUD and CUD but the strongest association was observed for new onset co-occurring alcohol and cannabis dependence (OR=4.51, CI=1.31-15.60).LimitationsThe present study is limited by the potential for social desirability and recall biases.DiscussionPositive associations between AUD, CUD and MDD were observed bidirectionally. Findings have implications for preventive and treatment programs and initiatives.