TBI as a Risk Factor for Substance Use Behaviors: A Meta-analysis

Objective To quantify the relationship between substance use behaviors before and after traumatic brain injury (TBI), to identify populations that may benefit more from targeted interventions to reduce the effect of substance use on TBI recovery, and to establish areas for further study. Data Sources Studies were identified via literature searches using MEDLINE, PsychInfo, PsychArticles, PubMed, and GoogleScholar (published before January 2019), as well as reference section reviews and forward searches. Searches were conducted using search terms for TBI and substance use behaviors. Study Selection Studies were included if they (1) contained both a measure of TBI and a measure of substance use behaviors; (2) reported an effect size representing the relationship between substance use behaviors before and after TBI, compared TBI vs non-TBI groups on substance use behaviors controlling for pre-TBI substance use, or compared groups with differing TBI severity on subsequent substance use behaviors controlling for pre-TBI substance use; (3) were written in English; and (4) were human subjects research. Studies examining effects of substance use intervention for people sustaining TBI were excluded from this study. Data Extraction Study variables included substance use behaviors, TBI severity, time since TBI, military status, age, race, and sex. Data Synthesis Substance use behaviors had a small but statistically significant decrease after moderate-severe TBI. After moderate-severe TBI, there was a statistically significant decline in both substance use (d=−0.29, P<.01) and negative substance use consequences (d=−0.67, P=.01). There was no significant change in substance use behaviors after mild TBI. Conclusions Substance use behaviors had a small decrease after moderate to severe TBI and no significant change after mild TBI. Study findings suggest the need for accurate assessment to identify those at greatest risk for problematic substance use behaviors after TBI.