Relating depression, anxiety, stress and loneliness to 5-year decline in physical function and frailty

Objectives: While depression has been associated with physical function decline and worsening frailty in older adults, the impact of other mental health symptoms on physical function and frailty is unknown. The study objective was to determine whether depression, perceived stress, loneliness, and anxiety symptoms affect 5-year physical function and frailty trajectories of older adults.

Methods: The National Social Life, Health, and Aging Project (NSHAP) is a nationally-representative study of adults born between 1920 and 1947. The analysis included data collected in 2010-11 and 2015-16. Mental health symptoms were quantified using NSHAP's measures of anxiety (range:0-21), perceived stress (0-8), depression (0-22), and loneliness (0-6); higher scores indicated worse symptoms. We regressed 2015-16 3 m usual walk time, five-repeated chair stand time or an adapted frailty phenotype scale (0-4) separately on each 2010-11 mental health scale, adjusting for baseline physical function or frailty, demographics, and comorbidities.

Results: In separate models, every one-point increase on the depression or perceived stress scales was associated with, respectively, a 0.06 s slower (95 % CI: 0.03, 0.10) or 0.09 s slower (95 % CI: 0.01, 0.16) 5-year walk time. Every one-point increase on the depression or perceived stress scales was associated with a 0.15 s slower (95 % CI: 0.06, 0.23) or 0.16 s slower (95 % CI: 0.02, 0.29) 5-year chair stand time. Every one-point increase on the depression scale predicted 0.06 higher log odds of having a worse frailty score 5 years later. Only depression's association with 3 m walk time and chair stands remained significant in models including all four mental health scales.

Discussion: Older adults with more depression and to a lesser extent stress symptoms may experience faster physical function decline and worsening frailty. Future work exploring and addressing the mechanisms underlying these relationships are warranted.

Keywords: Anxiety; Loneliness; Mental health; Physical function.