The most common forms of substance use in the United States are that of alcohol and cannabis use.  Harmful alcohol consumption is responsible for preventable illness, hospitalization, and mortality in a large subsect of the population, reaffirming the importance of treating alcohol misuse as early as possible.  While cannabis use has not been studied to the same extent as alcohol use, emerging research does indicate that the practice should not be considered harmless.  In fact, smoking cannabis may place individuals at higher risk for respiratory injury as well as mental health exacerbations.  When used together, alcohol and cannabis are thought to act in a synergistic fashion, creating an intensified intoxicated state.  This review paper presents the current directions of literature concerning alcohol and cannabis co-use.   

A total of 14 different articles concerning alcohol-cannabis co-use were reviewed by a team of authors before a series of summaries were produced.  Upon examination, the authors noted that the currently alcohol-cannabis co-use literature explores many different themes related to social context of the practice, general motives, prevalence, expectancies, and difficulties in obtaining accurate self-report measures.  The paper also mentions the presence of neuroimaging-based studies which help to develop a physiological basis for the effects of alcohol-cannabis co-use.  In general, the authors agreed that the current body of evidence suggests that the motives and effects of alcohol-cannabis co-use could be considered unique compared to using only one of the substances.  This could also be suggested of the consequences of the behavior as well. 

Takeaway: though the current body of literature concerning alcohol and cannabis co-use is relatively sparse, the available research does suggest that the practice produces effects and consequences that are considered unique.  Additional studies are necessary to determine more factors which may differentiate the nuances of the practice.

Linden-Carmichael, A. N., & Wardell, J. D. (2021). Combined use of alcohol and cannabis: Introduction to the special issue. Psychology of Addictive Behaviors, 35(6), 621-627. https://dx.doi.org/10.1037/adb0000772