The role of HPA-axis polygenic scores in shaping well-being during emerging adulthood: A multi-study approach

Emerging adulthood is a developmental period marked by both opportunity and vulnerability, where well-being depends heavily on effective stress regulation. Given that hypothalamic-pituitary-adrenal (HPA) axis is a key biological system in stress regulation, this multi-study explored how cumulative genetic variations in the HPA axis contribute to well-being during this stage. In Study 1, a cross-sectional analysis of 1318 participants, showed that a higher cumulative genetic score (CGS), reflecting more adaptive HPA-axis functioning, was significantly associated with greater scores on affect balance, life satisfaction, and overall flourishing. Study 2 used a longitudinal design (N = 348) and confirmed that these associations were stable over 12 months. Study 3 explored underlying mechanisms, demonstrating that the higher CGS predicted greater social adaptability and lower perceived stress, which mediated the link between the CGS and well-being. Together, this research indicates that the polygenic sensitivity of the HPA axis supports well-being through modifiable psychological pathways in emerging adulthood.