The interaction of social risk factors and HPA axis dysregulation in predicting emotional symptoms of five- and six-year-old children.

OBJECTIVE: We examined the links of social relational (family environment and peer victimization) and neuroendocrinological (HPA axis dysregulation) risk factors to children's emotional symptoms. We placed special emphasis on the joint effects of these risk factors with respect to the emergence and course of the emotional symptoms.
METHODS: One hundred and sixty-six children were interviewed (Berkeley Puppet Interview) at age 5 and 6. Teachers and parents completed the Strengths and Difficulties Questionnaire. Parents completed the Family Environment Scales. Peer victimization was assessed by teacher and child reports. Children's saliva cortisol was measured before and after a highly structured story completion task which targeted their cognitive emotional representations of family conflicts.
RESULTS: In the cross-sectional analyses, negative family environment, peer victimization, and cortisol increase during the story completion task independently contributed to the variance of emotional symptoms. There was a significant interaction effect between family environment and cortisol increase: those six-year-olds who had experienced an unfavorable family environment only showed high levels of emotional symptoms if they exhibited a cortisol increase during the story completion task. In the longitudinal analysis, peer victimization at age 5 predicted an increase of emotional symptoms at age 6, but only for those children who exhibited a blunted cortisol response a year earlier.
CONCLUSIONS: Negative family environment and peer victimization proved to be independently associated with emotional symptoms. HPA axis reactivity differentially moderated these associations. Therapeutic strategies should take the interaction between negative relational experiences and biological susceptibility to stress into account.