摘要：Objectives. We assessed whether households’ participation in the Supplemental Nutrition Assistance Program (SNAP) was associated with improvements in well-being, as indicated by lower rates of psychological distress. Methods. We used longitudinal data for 3146 households in 30 states, collected between October 2011 and September 2012 for the SNAP Food Security survey, the largest longitudinal national survey of SNAP participants to date. Analyses compared households within days of program entry to the same households approximately 6 months later. We measured psychological distress in the past 30 days on a 6-item Kessler screening scale and used multivariable regression to estimate associations between SNAP participation and psychological distress. Results. A smaller percentage of household heads exhibited psychological distress after 6 months of participation in SNAP than at baseline (15.3% vs 23.2%; difference = −7.9%). In adjusted models, SNAP participation was associated with a decrease in psychological distress (adjusted relative risk = 0.72; 95% confidence interval = 0.66, 0.78). Conclusions. Continuing support for federal nutrition programs, such as SNAP, may reduce the public health burden of mental illness, thus improving well-being among vulnerable populations. In 2012, 15% of all households in the United States were food insecure: their access to food was limited by a lack of income. 1 Among households in poverty, the prevalence was more than twice that of the general US population; an estimated 41% were food insecure. Persistently high rates of household food insecurity in the United States pose a significant problem, potentially affecting both physical and psychological well-being. 2,3 As the largest program in America’s nutrition assistance safety net, the Supplemental Nutrition Assistance Program (SNAP) provides nutrition assistance benefits to low-income individuals and families in an effort to reduce hunger and improve health and well-being. Several studies have documented an association between SNAP and improved food security, 4–7 including the most recent national-level study. 8,9 Although these studies have examined the program’s effectiveness in meeting one of its primary objectives—reducing hunger—its effectiveness in improving health and well-being has not been adequately assessed. The effects of SNAP on psychological well-being warrant considerable attention because estimates from the Behavioral Risk Factor Surveillance System, a survey of the US adult population, suggest that approximately 40% of persons in 35 states exhibit psychological distress (defined as a score of ≥ 10 on the 6-item Kessler screening scale [K6]). 10–12 In particular, women and people in lower socioeconomic positions have higher rates of psychological distress than does the general US population. 10 However, evidence suggests that the higher prevalence of mental illness observed among vulnerable populations may be a result of stressors associated with their common experiences rather than of demographic characteristics, such as race/ethnicity, education, or income. 13–15 In particular, growing evidence indicates that food insufficiency (a measure related to food insecurity) is strongly associated with adverse mental health outcomes. 3,16–21 Liu et al. reported that in a nationally representative sample, the prevalence of frequent mental distress was significantly greater among those reporting food insecurity (23.5%) than among their food-secure counterparts (7.7%). 21 Similarly, Heflin et al. explored food insufficiency among welfare recipients and found that the relationship between household food insufficiency and major depression remained highly significant, even after adjustment for factors known to increase the risk of depression. 3 Carter et al. also reported a strong relationship between food insecurity and psychological distress. 20 Increased social support is one way to mitigate the association between food insecurity and mental illness. 22,23 Although research is limited, participation in food assistance programs may be particularly effective in modifying the relationship between food insecurity and mental illness. 24,25 Certain nutrients, 26–28 overall diet quality, 29 and patterns of dietary intake 30,31 may be important in reducing the prevalence of adverse mental health outcomes. By reducing households’ exposure to food insufficiency, federal nutrition programs, such as SNAP, may improve well-being by reducing the public health burden of mental illness among vulnerable populations. We hypothesized that SNAP participation would result in decreased psychological distress, measured by the K6, among almost 3200 newly certified households that participated in the SNAP Food Security (SNAPFS) survey, which was conducted by Mathematica Policy Research for the US Department of Agriculture Food and Nutrition Service from October 2011 to September 2012. SNAPFS is the largest longitudinal food security survey of SNAP participant households to date.
