Aggression classification and treatment response.

This preliminary study investigated whether the aggression subtypes derived from the Aggression Questionnaire (AQ) are related to treatment response. The subjects were 28 aggressive conduct-disordered children (25 males, 3 females), ranging in age from 9.8 to 17.0 years (mean age = 12.69 years), who participated in a double-blind, placebo-controlled study of lithium as a treatment for reducing aggression. We used the Predatory-Affective Index of the AQ to classify subjects into "predatory" (planned) or "affective" (explosive) subtypes of aggression and then related this classification to treatment response. This index did not differentiate placebo baseline responders from nonresponders. However, the Index did significantly differentiate responders and nonresponders during the experimental treatment period, regardless of whether they received lithium or placebo. Treatment response was associated with a more affective and less predatory subtype of aggression. To the best of our knowledge, this is the first study in children to show an association between the aggression subtype and treatment response.