Physiological and Behavioral Vulnerability Markers Increase Risk to Early Life Stress in Preschool-Aged Children.

The study examined whether child physiological (cortisol reactivity) and behavioral (negative emotionality) risk factors moderate associations between the early rearing environment, as measured by child exposure to maternal depression and stressful life events, and preschool psychopathology and psychosocial functioning. A sample of 156 preschool-aged children (77 boys, 79 girls; age M = 49.80 months, SD = 9.57, range: 36-71) participated in an observational assessment of temperament and was exposed to a stress-inducing laboratory task, during which we obtained five salivary cortisol samples. Parents completed clinical interviews to assess child and parent psychopathology and stressful life events. Results indicated that the combination of a blunted pattern of cortisol reactivity and recent stressful life events was associated with higher levels of preschoolers' externalizing symptoms and lower psychosocial functioning. In addition, greater life stress was associated with higher levels of preschoolers' internalizing symptoms. Lastly, children with high levels of negative emotionality and who were exposed to maternal depression had the lowest social competence. Our findings highlight the critical role of the early environment, particularly for children with identified risk factors, and add to our understanding of pathways involved in early emerging psychopathology and impairment.