Allostatic load as a moderating factor between child maltreatment exposure and mental health challenges in children and adolescents: a study based on the EPI_Young_Stress Project.

Child maltreatment (CM) significantly impacts developing brains and bodies, increasing the risk of clinical conditions. Allostatic load (AL), conceptualized as an index of cumulative biological dysregulation, may function as a vulnerability marker that modifies the strength of the association between CM and emotional/behavioral symptoms. We aim to gain a better understanding of the mental health challenges in children and adolescents proximally exposed to CM and associated AL profiles. We studied 187 children and adolescents (7-17 years old) with and without current psychopathology. CM history was assessed using the TASSCV, and emotional/behavioral symptomatology with the CBCL. An AL index was derived from 10 biomarkers spanning neuroendocrine, immune, metabolic, and anthropometric systems, including diurnal cortisol output, cortisol reactivity, s-IgA output and reactivity during acute stress, CRP, glucose, HbA1c, total-to-HDL cholesterol ratio, BMI, and waist-to-height ratio (WHtR). Each participant received a risk score based on established clinical cut-offs to construct the composite AL-index. Findings indicated that CM was associated with higher AL scores (B = 0.18, p < .05), and AL significantly moderated the association between CM and emotional/behavioral symptomatology (B = 3.52, p < .05), particularly internalizing symptoms (B = 1.38, p < .05) and social problems (B = 0.48, p < .01). Notably, a combination of three biomarkers (diurnal cortisol, CRP and WHtR), most strongly predicted psychopathology severity in CM-exposed youth (B = 6.21, p < .05). In conclusion, children and adolescents with a history of CM already show increased AL, which reflects a state of biological vulnerability that amplifies the association between CM and mental health challenges. The 3-biomarker AL-index may represent a useful exploratory tool to identify individuals with more severe transdiagnostic symptom profiles.