background Investigation of neurobiological factors (e.g. hypothalamic-pituitaryadrenal (hpa) axis function, autonomic nerve system and executive functions) is necessary to obtain a clear insight into the etiopathogenesis of aggressive behavior, its prognosis and treatment. Converging evidence suggests that neurophysiological and neuropsychological profiles differ between reactive and proactive forms of aggression.
aim The aim of the present study is to investigate neurobiological underpinnings of adolescents engaging in proactive and reactive aggression.
methods A group of 33 male adolescents with proactive and/or reactive aggression and 20 age-matched healthy controls were included. A subdivision was made between proactive aggression and reactive aggression based on the repro, a Dutch translation of the Dodge & Coie questionnaire for proactive and reactive aggression. Testparadigm consisted of:
—— The Trier Social Stress Test for Children (tsst-c);
—— The determination of cortisol day curves and values after the tsst-c in (Cortisol-Salivettes);
—— The determination of the heart beat (Actiheart, Fypro);
——The measurement of the executive functions (cantab®-Cambridge Neuropsychological Test Automated Battery).
results In basic circumstances a blunted cortisol awakening response is seen among the aggressive population compared with a normal control population. Following the tsst-c differences are found between the control population and the aggressive population (blunted to no response at all). An increase in heart rate is seen in the aggressive population of male adolescents in basic conditions as well as after the tsst-c. An overall difference is seen in the proactive aggressive subpopulation on both neurophysiological parameters.
conclusion Investigation of biological factors regarding proactive and reactive may help to identify the predestination for developing aggressive behavior. Found differences in subgroups outline the probability of different neurophysiological pathways of the development of proactive and reactive aggression. This research is an essential first step preceding the research of predictive validity and the therapeutically relevance of the results.