Pathways from Social Support to Cognition Among Adults in the United States: A Longitudinal Mediation Analysis of Perceived Stress and Sleep Quality

Objective: We examined whether perceived stress and sleep quality mediate the association between social support and later cognition among adults in the United States. Methods: We used longitudinal Midlife in the United States (MIDUS) data. Social support (1995-1996) was modeled as a latent construct indicated by family and friend support. Perceived stress and sleep quality were measured in the MIDUS 2 Biomarker Project (2004-2009), and cognition was assessed in MIDUS 2 and MIDUS 3. Structural equation models evaluated parallel indirect pathways, adjusting for MIDUS 2 cognition and covariates. Results: Higher social support was associated with lower perceived stress ({beta}=-0.32, 95% CI:-0.41, -0.23) and better sleep quality ({beta}=-0.25, 95% CI:-0.35, -0.15). Greater perceived stress was associated with lower cognition ({beta}=-0.06, 95% CI:-0.11, -0.01), whereas sleep quality was not associated with cognition. Direct and total social support-cognition associations were not statistically significant. A small positive indirect association through perceived stress was identified ({beta}=0.02, 95% CI:0.00, 0.04); no indirect association through sleep quality was identified. Conclusions: Findings are consistent with a possible psychosocial pathway through perceived stress, although the effect was modest and total and direct associations were not statistically significant. Sleep quality showed no statistically significant indirect association.