Racial differences in depression in the United States: how do subgroup analyses inform a paradox?

Non-Hispanic Blacks in the US have lower rates of major depression than non-Hispanic Whites, in national household samples. This has been termed a "paradox," as Blacks suffer greater exposure to social stressors, a risk factor for depression. Subgroup analyses can inform hypotheses to explain this paradox. For example, it has been suggested that selection bias in household samples undercounts depression in Blacks; if selection is driving the paradox, Black-White differences should be most pronounced among young men with low education.

We examined Black-White differences in lifetime major depression in subgroups defined simultaneously by sex, age, and education using data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the Collaborative Psychiatric Epidemiology Surveys (CPES).

In NESARC and CPES, Blacks had lower odds than Whites of lifetime major depression in 21 and 23 subgroups, respectively, of 24. All statistically significant differences were in subgroups favoring Blacks, and lower odds in Blacks were more pronounced among those with more education.

These results suggest that hypotheses to explain the paradox must posit global mechanisms that pertain to all subgroups defined by sex, age, and education. Results do not lend support for the selection bias hypothesis.