Cortisol is inversely correlated with aggression for those boys with attention deficit hyperactivity disorder who retain their reactivity to stress

We examined the relationship between the cortisol response to stress and aggression in patients with attention deficit hyperactivity disorder (ADHD). Based on a report stating that only some of the patients with ADHD retain their hypothalamic-pituitary-adrenal axis reactivity to stress, we separately analyzed the relationship between aggression and the cortisol response to stress in two groups according to their reactivity to stress. Using psychological testing as an indicator of stress, we measured the cortisol level in the saliva before and after administering a psychological test. Behavioral problems, including aggression, were assessed using the Korean version of the Child Behavior Checklist (K-CBCL). The increase of the cortisol level was inversely correlated with aggression in patients who retained their reactivity to stress. The absolute value of the decrease was negatively correlated with the attention score of the CBCL for the patients who showed decreases in cortisol after stress. For the patients who showed increases in their concentration of cortisol in reaction to stress, cortisol may play a protective role against aggression.