Application of Syndemic Theory to Examine Intimate Partner Violence, Adverse Mental Health, and Food Insecurity on Polydrug Use Among a Sample of Low-Income Women

Background and Purpose: Intimate partner violence (IPV), adverse mental health, and substance misuse are serious intersecting public health problems. A highly gendered issue, nearly 1 in 2 women experience IPV, and numerous studies have demonstrated associations between IPV victimization and adverse mental health outcomes, and the use and misuse of substances. Low-income, food insecure women are particularly vulnerable to IPV and negative mental health sequelae as well as the risk of substance use. These myriad risks complicate service seeking, engagement, and retention in care, which is critical given that women are less likely than men to be engaged in substance use treatment. Despite this research, few studies have examined the unique impact of intersecting IPV, mental health symptoms, and food insecurity on substance use. Drawing on syndemic theory, this paper examines the interaction effects of IPV, mental health, and food insecurity on substance use, specifically polydrug use.

Methods: Two-hundred individuals, recruited from a large community-based organization serving low-income, under/unhoused individuals in a U.S. Southwestern state, participated in a cross-sectional survey in 2022 as part of a broader mixed-methods study. Eligible participants (at least 18 years old, receiving services, and fluent in English or Spanish) who provided consent completed a survey using tablets (with/without assistance) that captured socio-demographics, IPV, mental health symptoms, food insecurity, and drug use among other factors. Data reported here rely on the sub-sample of 79 participants who identified as women. Descriptive statistics and correlation analyses were conducted to characterize the sample and examine variables of interest. Examining the primary research question, two separate ordinal logistic regression models were executed in Mplus. Each model included main effects for food insecurity, IPV, and mental health (Model 1: depressive symptoms; Model 2: post-traumatic stress symptoms (PTSS)) as well as all possible two- and three-way interactions as predictors of drug use (none, mono-drug use, polydrug use). Significant interactions were then interpreted using simple slopes analyses.

Results: The mean age of participants was 46.5 years old (SD=12.4). Nearly half of the participants identified as White (46.5%) while 30.4%, 13.9%, 5.1%, and 3.8% identified as Hispanic/Latinx, Black/African American, Multi-racial, and American Indian/Alaskan Native, respectively. Bivariate correlations showed that higher IPV, mental health symptoms, and food insecurity were associated with higher drug use. Model 1 showed a main effect of depression (OR=2.39, p<.05) on drug use. Model 2 showed main effects of food insecurity (OR=7.0, p<.05) and PTSS (OR=1.45, p<.05) on drug use; these significant main effects were superseded by a statistically significant three-way interaction of IPV-PTSS-food insecurity on drug use (OR=0.38, p<.05). Simple slope analyses revealed unique patterns by low/high IPV and PTSS with high food insecurity on polydrug use.

Conclusions and Implications: Findings provide support for an IPV-PTSS-food insecurity syndemic on polydrug use among low-income women. Overall, the findings suggest the need for expanded examinations of the role of food insecurity alongside other risks on substance use, especially among larger samples of women and given the disproportionate rates of food insecurity among women. Findings also suggest practical implications, including integrated service planning.