Association of psychosocial stress with altered functional connectivity of large-scale brain networks in aging adults.

Although evidence suggests that psychosocial stress is a risk factor for cognitive decline in aging adults, potential mechanisms for this association are not well understood. This cross-sectional study examined associations of two measures of self-reported psychosocial stress, including the perceived stress scale (PSS) and a stressful life events (SLE) questionnaire, with functional connectivity in four large-scale, nonoverlapping brain networks derived from resting-state functional magnetic resonance imaging (rs-fMRI). Analyses included 426 late middle-aged and older participants from the Healthy Minds for Life study of the Precision Aging® Network (M (SD) age = 64.5 (7.8) years, 71% female, 33% from underrepresented racial/ethnic groups). Higher SLE scores were associated with lower functional connectivity in the default mode, salience/ventral attention, and dorsal attention networks. Higher SLE scores were additionally associated with lower cognitive performance. Patterns of results were similar when individuals with possible cognitive impairment were excluded. These findings indicate that higher levels of psychosocial stress, particularly stressful life events, are associated with lower connectivity in several large-scale functional brain networks and suggest one mechanism by which everyday experiences may shape the aging brain.