Depressive Multimorbidity and Trajectories of Functional Status among Older Americans: Differences by Racial/Ethnic Group.

Objective: This study aims to evaluate the impact of depressive multimorbidity (ie, including depressive symptoms) on the long-term development of activities of daily living (ADL) and instrumental activities of daily living (IADL) limitations according to racial/ethnic group in a representative sample of US older adults.

Design: Prospective, observational, population-based 16-year follow-up study of nationally representative sample.

Setting And Participants: Sample of older non-Hispanic Black, Hispanic, and nonHispanic White Americans from the Health and Retirement Study (2000‒2016, N = 16,364, community-dwelling adults ≥65 years of age).

Methods: Data from 9 biennial assessments were used to evaluate the accumulation of ADL-IADL limitations (range 0‒11) among participants with depressive (8-item Center for Epidemiologic Studies Depression score≥4) vs somatic (ie, physical conditions only) multimorbidity vs those without multimorbidity (no or 1 condition). Generalized estimating equations included race/ethnicity (non-Hispanic Black, Hispanic, non-Hispanic White), baseline age, sex, body mass index, education, partnered, and net worth.

Results: Depressive and somatic multimorbidity were associated with 5.18 and 2.95 times greater accumulation of functional limitations, respectively, relative to no disease [incidence rate ratio (IRR) = 5.18, 95% confidence interval, CI (4.38,6.13), IRR = 2.95, 95% CI (2.51,3.48)]. Hispanic and Black respondents experienced greater accumulation of ADL-IADL limitations than White respondents [IRR = 1.27, 95% CI (1.14, 1.41), IRR = 1.31, 95% CI (1.20, 1.43), respectively].

Conclusions And Implications: Combinations of somatic diseases and high depressive symptoms are associated with greatest accumulation of functional limitations over time in adults ages 65 and older. There is a more rapid growth in functional limitations among individuals from racial/ethnic minority groups. Given the high prevalence of multimorbidity and depressive symptomatology among older adults and the availability of treatment options for depression, these results highlight the importance of screening/treatment for depression, particularly among older adults with socioeconomic vulnerabilities, to slow the progression of functional decline in later life.