Health Insurance as a Moderator of Cardiovascular Risk Among Adults with Depression: A Cross-Sectional and Geographic Analysis Using BRFSS 2019–2023 Data

Background: Depression is a key psychosocial risk factor for cardiovascular disease (CVD); however, the degree to which lack of health insurance amplifies this risk remains unclear. Geographical disparities in mental health, cardiovascular outcomes, and insurance coverage further complicate prevention efforts. Understanding the interplay between these factors is crucial for planning targeted interventions to mitigate population-level cardiovascular risk. Objective: To assess whether health insurance modifies the relationship between depression and CVD among adults and to illustrate geographic disparities in combined mental health, cardiovascular risk, and insurance burden across US states and territories. Methods: We analyzed Behavioral Risk Factor Surveillance System (BRFSS) data from 2019 to 2023, including adults aged ≥18 years with complete data on depression, CVD, and health insurance status (n = 457,670). Logistic regression models were employed to estimate the relationship between depression and CVD, adjusting for demographic and behavioral risk factors. An interaction term between depression and lack of health insurance was included to examine moderation. State-level prevalence estimates were used to construct a four-tier composite burden index incorporating depression, CVD, and rates of lack of health insurance. Choropleth maps were developed to depict geographic patterns. Results: Overall, 21.1% of adults were found to have depression, 12.3% had CVD, and 5.8% had no health insurance. Depression was significantly associated with CVD (adjusted OR = 1.69; 95% CI: 1.65–1.72). Lack of health insurance significantly moderated the relationship between depression and CVD (interaction OR = 1.33; 95% CI: 1.18–1.51, p < 0.001). Geographic mapping analyses demonstrated marked heterogeneity. Tier 4 (highest burden) states included Kentucky, West Virginia, Louisiana, Oklahoma, Texas, New Jersey, Guam, and the U.S. Virgin Islands. Many Tier 3 and Tier 4 regions were clustered in the South and Appalachia. Conclusions: Depression is strongly associated with an increased prevalence of CVD, and this association is further amplified among individuals without health insurance coverage. Geographic disparities demonstrate critical hotspots where simultaneous mental health challenges, elevated risk of CVD, and limited insurance converge, highlighting the need for combined, area-specific public health strategies and approaches addressing both mental and cardiovascular health.