Since adulthood antisocial, aggressive and delinquent behaviors often have their onset early in life, investigating the association between biological factors and disruptive behaviors in children and adolescents are important and are emphasized on in the recent years. Baseline cortisol level seems to be a valuable biological marker of individuals with Disruptive Behavior Disorder (DBD). This study examined the effect of parent training on salivary cortisol levels of children with DBD.

Saliva samples were assayed to determine cortisol levels in nineteen clinic-referred children with DBD (aged 8 through 13 years) before and after an eight-session parent training program. Children's disruptive behaviors were assessed by Child Behavior Check List before and after the intervention.

Children's salivary cortisol increased significantly after parent training sessions. Children with DBD who had lower basal cortisol levels had more severe disruptive behaviors and a better response to intervention by parent training as assessed by changes in cortisol levels and disruptive behaviour scores. However, post-interventional reduction of disruptive behaviors and increase in cortisol level was significant for all levels of baseline cortisol.

Parent training is an effective method for behavioral modification in DBD. Salivary cortisol may be considered a predictive factor for severity of the child or adolescent's disruptive behaviors and also for response of those behaviors to parent training.