A meta-analytic investigation of the associations between cannabis use and cannabis-related negative consequences

In the current climate of policy change regarding cannabis (i.e., decriminalization, medicalization, and legalization), various stakeholders have a strong interest in determining the associations between cannabis use and important outcomes. The present study sought to quantify the association between indicators of cannabis use and the experience of cannabis-related negative consequences. We found 19 unique studies that examined the associations between cannabis use and negative consequences as measured by 1 of 4 measures: the Marijuana Problems Scale, the Rutgers Marijuana Problem Index, the Cannabis Problems Questionnaire, or the Marijuana Consequences Questionnaire. We used random effects meta-analytic techniques to estimate the average strength of association between cannabis use and negative consequences, determine the level of heterogeneity in effect sizes, and examine possible moderators of these associations (measure of consequences, gender/sex distribution). We found that cannabis use had a medium-sized association with consequences, rw = .367, with high levels of heterogeneity that depended to some extent on the specific consequence measure used. Similar to a meta-analytic integration of the alcohol use-consequences association, we found that most of the variance in cannabis-related negative consequences was not explained by any single indicator of cannabis use, pointing to the fact that additional factors need to be examined to explain the experience of negative consequences from cannabis use and that additional indicators of cannabis use may be needed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).