Association between maltreatment, hair cortisol concentration, positive parent–child interaction, and psychosocial outcomes in Chinese preschool children

Children now are facing an increasing risk of early life stress (ELS), which leads to detrimental psychosocial outcomes. Behavior studies suggested that positive parental interactions might moderate the negative impact of ELS, but the related biological alteration remains unclear. This study aims to investigate whether positive parent–child interactions moderate the association between maltreatment (as a severe form of ELS) and hair cortisol concentration (HCC), as well as between HCC and psychosocial outcomes in young children. Participants were 6-year-old Chinese children ( N = 257, M age = 6.2, 121 were male) selected by stratified cluster random sampling from a Shanghai population representative cohort. Proximal 3 cm hair strands were analyzed using liquid chromatography coupled with tandem mass spectrometry for HCC. Children’s psychosocial outcome was evaluated using the parental report Strengths and Difficulties Questionnaire (SDQ). Parents also reported the frequency of positive parent–child interactions using the Chinese Parent–Child Interaction Scale (CPCIS) as well as the history of maltreatment. Multi-level logistic regression models adjusting for individual, kindergarten, and district confounders were used to evaluate the associations between maltreatment, HCC, and psychosocial outcomes. Interactions terms tested whether more frequent positive parent–child interactions moderates the association between maltreatment and HCC, as well as between HCC and psychosocial outcomes. Maltreated children exhibited higher levels of HCC ( B = 1.20, 95% CI: 0.38,2.02; p = 0.004), and children with higher HCC exhibited poorer psychosocial outcomes ( B = 0.34, 95% CI: 0.18,0.51; p < 0.001). Positive parent–child interactions did not have a moderating effect on the association between maltreatment and HCC, but they demonstrated a moderating effect on the association between increased HCC and psychosocial outcomes (interaction term: B = −0.42, 95% CI: −0.75,−0.10; p = 0.01). These findings provide evidence that positive parental interaction may serve as a moderator between chronic cortisol exposure and psychosocial problems. It highlights the importance of frequent parent–child interactions, especially among children under a high risk of ELS.