The Role of Financial Strain in Adult Alcohol, Cannabis, CNS Depressant and Polysubstance Use, and Mitigating Effects of Earned Income Tax Credit Policies: a Longitudinal Study using PATH data

PROJECT SUMMARY/ ABSTRACT Financial strain and substance use are widespread in the United States (US), as many adults struggle to meet basic financial needs. Financial strain is distinct from its sources (e.g., job or income loss), as perception of strain may be necessary to produce a stress-response that prompts substance use as a coping mechanism. Studies examining the relationship between financial strain and substance use have focused on the association between financial strain and alcohol use, or acute financial strain due to sudden changes in job or income. However, there is a need to examine whether the relationship between financial strain and substance use varies by substance, and the duration of financial strain (i.e., acute financial strain due to sudden job or income loss, chronic financial strain due to persistent deprivation, or intermittent financial strain due to repeated periods of economic insecurity). Anti-poverty programs such as the federal Earned Income Tax Credit (EITC) may provide an opportunity to reduce financial strain and subsequent substance use by providing financial support to low-income populations. The current R36 proposal seeks to provide novel insights about the associations between acute, chronic, or intermittent financial strain and cannabis, CNS depressant, alcohol, and polysubstance use, and whether federal EITC eligibility alters these relationships. To achieve these goals, we propose three aims that will leverage individual- and state-level data from 5 waves (2013-2019) of the Population Assessment of Tobacco and Health study, a longitudinal cohort of >30,000 US adults. Aim 1 will examine the association between financial strain and cannabis, CNS depressant, alcohol, or polysubstance use at subsequent time points using parametric g-computation, accounting for time-varying confounding, and examining effect modification by sex. Aim 2 will create exposure trajectories of financial strain (i.e., none, acute, chronic, and intermittent) across four waves of data collection, and examine the risk of cannabis, CNS depressant, alcohol, or polysubstance use at Wave 5 using a mixed model to adjust for substance use trajectories and recency of financial strain. Aim 3 will examine whether federal EITC eligibility is associated with short-term changes in financial strain, cannabis, CNS depressant, alcohol or polysubstance use, and whether financial strain mediates the relationship between federal EITC eligibility and substance use, examining effect modification by sex and state EITC. This project will advance NIDA’s research priority to support dissertation research examining social factors that influence drug use outcomes, and determine how policies affect drug use trends. Findings from this R36 study will help identify individuals at risk for substance use, inform policies seeking to alleviate financial strain, and will inform a future K award application. The proposed project and mentorship team will provide the principal investigator with the opportunity to develop expertise at the intersection of health economics, substance use epidemiology, and policy research, in pursuit of her long-term goal of becoming an independent researcher at an academic institution.