HPA-SAM Co-Activation among Racially Diverse, Economically Disadvantaged Early Adolescents: Secondary Analysis with a Preliminary Test of a Multisystem, Person-Centered Approach

Investigating the co-activation of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenomedullary (SAM) responses to acute stress can provide insight into how risk might become biologically embedded dur -ing early adolescence and improve understanding of what distinguishes physiological dysregulation from normative/expected physiological responses to stress. Evidence has thus far been mixed as to whether symmetric or asymmetric co-activation patterns are associated with higher exposure to chronic stress and poorer mental health outcomes during adolescence. This study expands on a prior multisystem, person-centered analysis of lower-risk, racially homogenous youth by focusing on HPA-SAM co-activation patterns in a higher-risk, racially diverse sample of early adolescents from low-income families (N = 119, M-age=11.79 years, 55.5% female, 52.7% mono-racial Black). The present study was conducted by performing secondary analysis of data from the baseline assessment of an intervention efficacy trial. Participants and caregivers completed questionnaires; youth also completed the Trier Social Stress Test-Modified (TSST-M) and provided six saliva samples. Multitrajectory modeling (MTM) of salivary cortisol and alpha-amylase levels identified four HPA-SAM co-activation profiles. In accordance with the asymmetric-risk model, youth exhibiting Low HPA-High SAM (n = 46) and High HPA-Low SAM (n = 28) profiles experienced more stressful life events, posttraumatic stress, and emotional and behavioral problems relative to Low HPA-Low SAM (n = 30) and High HPA-High SAM (n = 15) youth. Findings highlight potential differences in biological embedding of risk during early adolescence based on individuals' exposure to chronic stress and illustrate the utility of multisystem and person-centered approaches in understanding how risk might get "underneath the skin" across systems.