Low salivary cortisol and persistent aggression in boys referred for disruptive behavior

Background: Persistent antisocial behavior in adulthood is often preceded b y childhood-onset aggressive conduct disorder. Aggressive syndromes in both children and adults have previously been associated with abnormalities in peripheral responses to stress. One peripheral measure, salivary cortisol c oncentration, may reflect individual differences in the hypothalamic-pituit ary-adrenal axis that underlie propensities for aggression, socialization, and adaptation to stress. Methods: The relationship between salivary cortisol levels and aggression w as tested in 38 clinic-referred school-aged boys. Persistent aggression was measured by collecting disruptive behavior disorder symptoms in 4 annual c linical evaluations and peer nominations of aggression in the first 2 annua l evaluations. Salivary cortisol levels were measured during years 2 and 4 of the study. Results: Low cortisol levels were associated with persistence and early ons et of aggression, particularly when measures of cortisol concentrations wer e pooled. Boys with low cortisol concentrations at both time points exhibit ed triple the number of aggressive symptoms and were named as most aggressi ve by peers 3 times as often as boys who had higher cortisol concentrations at either sampling time, Conclusions: This suggests that low hypothalamic-pituitary-adrenal axis act ivity is a correlate of severe and persistent aggression in male children a nd adolescents. A restricted (low) range of cortisol variability may be mor e indicative of persistent aggression than a low concentration of cortisol at any single point in time.