I am what I am: A meta-analysis of the association between substance user identities and substance use-related outcomes.

Abstract

Research indicates that a substance user identity (i.e., drinking, smoking, and marijuana identity) is positively correlated with substance use-related outcomes (e.g., frequency, quantity, consequences, and disorder symptoms). The current study aimed to meta-analytically derive single, weighted effect size estimates of the identity-outcome association as well as to examine moderators (e.g., substance use type, explicit/implicit assessment, demographic characteristics, and research design) of this association. Random effects meta-analysis was conducted on 70 unique samples that assessed substance user identity and at least one substance use-related outcome (frequency, quantity, consequences, and/or disorder symptoms), and provided the necessary information for effect size calculations. Substance user identity was found to be a statistically significant moderate-to-large correlate of all substance use-related outcomes examined in the current study (r w = .365, p < .001, rw² = .133). The strongest associations were observed between identity and disorder symptoms (alcohol) and frequency of substance use (tobacco or marijuana). In terms of moderators of the identity-outcome association, the link between explicit drinking identity and alcohol use-related outcomes appeared to be stronger in magnitude than the relationship between implicit drinking identity and alcohol use-related outcomes; however, this difference appears to be largely due to the finding that implicit measures have lower reliability. The strongest identity-outcome association was observed among younger individuals. Substance user identity is clearly an important correlate of substance use-related outcomes and this association is stronger among younger individuals. Additional theoretical, empirical, and intervention research is needed to utilize knowledge gleaned from the current study on the identity-outcome association. (PsycInfo Database Record (c) 2021 APA, all rights reserved).