Income and Mental Well-Being of Middle-Aged and Older Americans: Immigrants’ Diminished Returns

Although income is among the major social determinants of mental health of middle-aged and older individuals, socially marginalized groups gain less health from their income and other socioeconomic status (SES) resources compared to socially privileged groups. This pattern is called marginalization-related diminished returns (MDRs). Most of the existing knowledge on MDRs, however, has been derived from studies that have defined marginalization based on race, ethnicity, or sexual orientation. As a result, very limited information exists on whether similar MDRs can be observed for middle-aged and older immigrants or not. Building on the MDRs framework, this study compared a national sample of immigrants and non-immigrants for the effects of income on the mental well-being of middle-aged and older adults in the United States. This is a cross-sectional study. The 2015 National Health Interview Survey (NHIS) enrolled 14 149 middle-aged and older individuals who were either immigrants (n=1977; 14.0%) or non-immigrants (n=12 166; 86.0%). The independent variable (IV) was income that was treated as a continuous variable. The dependent variable was mental well-being, also treated as a continuous variable. Age, gender, race, ethnicity, education, marital status, employment, self-rated health, obesity, and region were confounders. Immigration (nativity status) was the moderator. Logistic regression was applied for data analysis. High income was associated with higher odds of good mental well-being in middle-aged and older adults. However, immigration showed a significant statistical interaction with income, which was suggestive of a smaller protective effect of high income on mental well-being for immigrant than non-immigrant middle-aged and older adults. In line with MDRs, the association between income and mental well-being is weaker for immigrant than non-immigrant middle-aged and older adults. There is a need to help high income immigrants secure health outcomes similar to those of non-immigrants. Such changes may require bold and innovative economic, public, and social policies that help immigrants more effectively translate their income and socioeconomic resources into tangible outcomes such as mental well-being.