Substance Use and Self-Reported Mental Health: The Moderating Effect of Acquaintance Use Behavior among Adults

A considerable body of literature has documented the positive effects that social relationships have for mental health. Similarly, a number of studies have demonstrated the importance of peer and acquaintance networks in attempts to understand substance use. The present study brings together these disparate fields and examines the relationship between individual alcohol and marijuana use and self-reported mental health, and, in particular, whether acquaintance substance use behavior may, under certain conditions, moderate this association by providing a normative context of acceptance. Based on an analysis of a community-based sample of 23,932 adults from 41 mid-sized cities nationwide, the findings indicate that in addition to the detrimental relationship between individual's substance use and mental health, substance use on the part of acquaintances increases the odds of reporting poor mental health, irrespective of the respondent's own use or non-use. However, the relative effect of acquaintance substance use behavior is smaller for those individuals who use than for those who do not: among users of alcohol and marijuana, having acquaintances who also use is associated with a lesser increase in odds as compared to those who do not use but whose acquaintances do. These results suggest that the degree of normative congruity between individual behavior, the “local” context formed by peers and associates, and the broader societal context is a variable factor which is implicated in the relation between substance use and mental health.