Disruptive behaviors and HPA-axis activity in young adolescent boys and girls from the general population.

It is important to investigate associations between biological factors and disruptive behaviors in children and adolescents. Antisocial, aggressive, and criminal behaviors in adults often begin early in life. Disruptive behaviors are often thought to be associated with low activity of the hypothalamic-pituitary-adrenal (HPA) axis. Cortisol, the end-product of this axis, can be measured to investigate HPA-axis activity. Previous studies on this topic concerned clinical or high risk samples. The aim of the present study was to investigate to which extent HPA-axis functioning plays a role in disruptive behaviors in pre-adolescents from the general population. One thousand seven hundred and sixty eight 10- to 12-year-olds from the Dutch general population were investigated. Disruptive behaviors were assessed with the Child Behavior Checklist, the Youth Self-Report, and the Antisocial Behavior Questionnaire. Baseline morning and evening salivary cortisol levels were assessed. Unexpectedly, small associations were found between disruptive behaviors, including attention problems, and higher cortisol levels. However, all effect sizes of significant effects were very small. Our study indicated that HPA-axis functioning may be more relevant in clinical or high risk samples than at the general population level. The association between HPA-axis functioning and attention problems, that has gotten less attention than that with aggressive or delinquent behaviors, requires further research. Furthermore, because effect sizes were relatively small, it can be concluded that, in pre-adolescence, the measures of baseline HPA-axis functioning that were used for the present study can not be used as biological markers for disruptive behaviors.