2008

Contradictory findings on the relationship between hypothalamus-pituitary-adrenal (HPA)-axis activity and externalizing behavior problems could be due to studies not accounting for issues of comorbidity and gender. In a population-based cohort of 1768 (10- to 12-year-old) early adolescents, we used a person-oriented approach and a variable-oriented approach to investigate whether comorbidity with internalizing behavior problems and gender moderate the relationship between HPA-axis activity (cortisol awakening response and evening cortisol levels) and externalizing behavior problems. We found that: (1) in early adolescents with pure externalizing behavior problems, there was a particularly strong effect of gender, in that girls showed significantly higher total cortisol levels after awakening (AUC(G) levels) and a significantly higher cortisol awakening response (AUC(I) levels) than boys. (2) Girls with pure externalizing behavior problems showed a significantly higher cortisol awakening response (AUC(I) levels) than girls without behavior problems or girls with comorbid internalizing behavior problems. This effect was absent in boys. (3) Externalizing behavior problems, in contrast to internalizing behavior problems, were associated with higher evening cortisol levels. This effect might, however, result from girls with externalizing behavior problems showing the highest evening cortisol levels. Overall, we were unable to find the expected relationships between comorbidity and HPA-axis activity, and found girls with pure externalizing behavior problems to form a distinct group with regard to their HPA-axis activity. There is need for prospective longitudinal studies of externalizing behavior problems in boys and girls in relation to their HPA-axis activity. It would be useful to consider how other risk factors such as life events and family and parenting factors as well as genetic risks affect the complex relationship between externalizing behavior problems and HPA-axis activity.

Low HPA-axis activity has been proposed as a risk factor for disruptive behaviors. However longitudinal data on this topic are practically lacking. In the present study we investigated if low HPA-axis activity predicted future disruptive behaviors. We included 1,399 boys and girls from the Dutch general population, initially aged 10–12 years. At the first assessment, basal cortisol levels were assessed. At the first assessment and at follow-up 2 years later disruptive behaviors were assessed with parent and self-report questionnaires. The results suggest that the association between low cortisol levels at 8.00 p.m. and future disruptive behaviors according to the parents was only present for boys. More importantly however, the results suggest that low HPA-axis activity is not a good predictor for disruptive behaviors, but could be valuable to identify those with a poor prognosis, once disruptive behaviors are present in preadolescence.

There has been recent emphasis on the importance of investigating prosocial and antisocial behavior simultaneously owing to doubts whether examining one automatically gives information about the other. However, there has been little empirical research into this question. The present study (based on a large population sample of preadolescents, N = 2,230) examines simultaneously prosocial and antisocial behavior, explicitly including the possibility that children might show prosocial behavior according to one informant and antisocial behavior according to another. When parent and teacher agreed in their judgments, children were distinctly profiled and differed clearly in effortful control, intelligence, academic performance, and several peer nominations and family characteristics. The correlates were more rater-specific for children that were prosocial according to one informant and antisocial according to the other informant. Teachers and parents used different context-dependent criteria for judging children to be prosocial or antisocial. Academic performance and peer relations were related to the teacher’s judgment of prosocial and antisocial behavior. By contrast, childrens being problematic at home (and thus causing stress for the parents) were related to the parents’ judgment.