Decision-Making Under Stress, Biological Stress Responses, and Risk for Suicidal Behavior in Young Adults

Background: Stress may influence decision-making processes relevant to suicidal behavior, yet few studies have examined risky decision-making and expected value (EV) sensitivity under stress longitudinally among young adults at elevated suicide risk. Methods: Participants included 233 young adults (18-30 years) with recent suicide attempts (n=55), suicidal ideation (n=59), psychiatric controls (n=71), and healthy controls (n=48). Hair cortisol concentration, circulating inflammatory markers (CRP, IL-6, IL-10, IL-1ra, TNF-alpha), Stressful Cups Task, and clinical measures were assessed at baseline, 3-, 6-, and 12-month follow-ups. Results: Participants with a history of suicide attempts showed greater reductions in risky choices under stress over time compared to healthy controls. Greater reductions in EV sensitivity under stress relative to neutral conditions predicted subsequent suicidal behavior. Higher C-reactive protein (CRP) was associated with fewer risky choices under both neutral and stress conditions, while higher interleukin-6 (IL-6) was associated with fewer risky choices under neutral conditions. Higher interleukin-10 (IL-10) was associated with greater reductions in risky choices under stress relative to neutral conditions over time. No significant associations were observed for hair cortisol concentrations (HCC). Conclusions: Stress-related changes in risky decision-making and reduced EV sensitivity may contribute to vulnerability to suicidal behavior. These findings highlight the importance of assessing decision-making under stress and examining inflammatory processes as potential mechanisms underlying suicide risk.