Identifying biobehavioral pathway from social isolation to suicidality in older Americans

Document Type

Conference Proceeding

Publication Date

4-1-2025

Publication Title

J Am Geriatr Soc

Abstract

Background: Suicidality is a major public health concern that accounts for death and disability worldwide. Specific to late adulthood, higher suicide risk is also attributed to elevated social isolation. However, the biobehavioral pathway linking social isolation and suicidality in late life is yet uncovered. Methods: This observational study aims to combine genetic and social factors to better understand suicide risk in older adults aged 65 orabove, leveraging on diverse longitudinal cohorts from All of Us (AoU)program. It included 25,010 or 1,433 older adults of European (EUR) ornon-EUR descent, respectively. Suicidality outcome was defined using records for suicide attempts or suicide ideations. Social isolation was assessed by MOS social support and UCLA loneliness surveys. Genetic vulnerability was proxied by polygenic risk scores (PRS), summarizingmultiple genetic variants across genome. Univariable and multivariable logistic regressions were performed to identify suicidality-related asso-ciates among factors from social isolation and genetic vulnerability,adjusting for age, gender, and marital status. Structural equation models were then used to test whether inflammatory markers in blood (whiteblood cell counts, c-reactive protein, and Immunoglobulin G) were involved in the causal pathway as potential mediators. Results: Analyses revealed significant association between two socialisolation domains and suicidality outcome in both EUR and non-EURgroups (p<0.0001). Genetic diathesis for suicide and loneliness werealso significantly higher (p<0.001) in older EUR Americans with history of suicide attempts or ideations. When testing these factors together, the conditional associations for UCLA loneliness and suicide PRS remained significant, but their interaction effects were not. Causal models revealed the intrinsic connection from different domains of social isolations tosuicidality in older population and identified a few inflammatory mark-ers significantly mediated the transitional process (p<0.05). Conclusions: Our findings provide new insights on suicidality across diverseolder populations, suggesting that integration of genetic counseling,peripheral inflammation, and social isolation assessment into practice could help identify and serve individuals at higher risk. Validation is on-going with a regional community cohort collecting from Metro Detroit area.

Volume

73

First Page

S189

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