Sleep Health As a Mediator between Food Insecurity and Depression Among American Indians in South Dakota

Background and Purpose: The association between food insecurity and depression is well documented in the United States. However, American Indians are often aggregated with other racial and ethnic identities or excluded altogether due to the small sample size. Understanding the relationship between food insecurity and depression within American Indian populations is critical, as Native American communities have disproportionately higher rates of mental health conditions and food insecurity. Furthermore, while food insecurity is also associated with poor sleep health, little is known about the relationship between food insecurity, sleep health, and depression. Thus, guided by Social Determinants of Health framework, this study investigates the link between food insecurity and depression among Yankton Sioux Tribe (YST) members, focusing on sleep health as a mediator.

Methods: A community-based participatory research (CBPR) approach guided the study, as part of a larger collaborative effort with the Yankton Sioux Tribe (YST) in South Dakota. A cross-sectional survey was conducted in September 2024 among adults from the YST (N = 248). Participants were recruited through community events (e.g., powwows) using convenience and snowball sampling methods. Food security was measured with the validated three-item Social Needs Screening Tool. Sleep health was measured using two self-reported items (From the National Study of Caregiving). Each measure was combined into a sum score to represent overall food security and sleep quality. Depression was assessed using PHQ-2. All data are considered joint property of the investigators and the Tribe.

Results: Half of respondents identified as female with a mean age of 45 years (range: 18-81). 64% of the sample reported a monthly income of less than $3,000. Following the Baron and Kenny (1986) approach to test for mediation controlling for age and gender, first, food insecurity significantly predicted depression (b = 0.132, SE = 0.047, z = 2.813, p = .005). Second, food insecurity was a significant predictor of sleep health (b = 0.467, SE = 0.133, z = 3.505, p < .001). Third, sleep health significantly predicted depression while controlling for food insecurity (b = 0.219, SE = 0.018, z = 12.273, p < .001). When sleep health was included in the model, the direct effect of food insecurity on depression became non-significant (b = 0.030, SE = 0.038, z = 0.787, p = .431), indicating full mediation. Also, the indirect path remained significant (b = 0.102, p = .001), suggesting that food insecurity contributes to depression through its impact on sleep health.

Conclusions and Implications: Sleep health mediates the relationship between food insecurity and depression among YST participants. Our findings highlight sleep as a potential intervention target to reduce the mental health impacts of food insecurity in American Indian communities. Future efforts should be co-designed with tribal partners to improve sleep quality and duration. Future research is needed with other tribal communities to confirm these findings and to better understand both the unique and common factors influencing food insecurity, sleep health, and depression among Indigenous populations.