THE DOMINANCE OF BEHAVIORAL ACTIVATION OVER BEHAVIORAL-INHIBITION IN CONDUCT-DISORDERED BOYS WITH OR WITHOUT ATTENTION-DEFICIT HYPERACTIVITY DISORDER

On the basis of Gray's theory, Quay suggested that conduct disorder (C D) is associated with a Behavioural Activation System (BAS) that domin ates over the Behavioural Inhibition System (BIS), whereas attention d eficit hyperactivity disorder (ADHD) is characterised by an underactiv e BIS. Two studies were conducted to test the hypothesis that the domi nance of the BAS over the BIS is more pronounced in CD comorbid with A DHD (CD/ADHD) than in CD alone. First of all, a response perseveration task was used, i.e, the door-opening task (Daugherty & Quay, 1991). I n this game, the subject chooses either to open the next door or to st op playing; there is a steadily increasing ratio of punished responses to rewarded responses and a large number of doors opened is indicativ e of response perseveration. As expected, a steady increase in the num ber of doors opened was found across normal control (NC) boys, CD boys , and CD/ADHD boys (NC < CD < CD/ADHD). Second, the dominance of the B AS over the BIS was examined by observing the social behaviour of the child in interaction with a research assistant who alternately activat ed the BAS and the BIS while a game was played. The behaviour of the c hildren was analysed according to ethological methods. Group differenc es in the frequencies of three out of we behavioural categories were i n line with the results of the door-opening task (NC < CD < CD/ADHD).