Autonomic activity in boys with disruptive behavior disorders

Skin conductance (SC) and heart rate (HR) were measured during rest, a series of tones, and a reaction time task in 34 boys with disruptive behavior disorder to ascertain (a) if this broadly defined group differed from control boys (n = 33) and (b) if there were differences within the spectrum related to component diagnoses or to target behaviors. Disruptive boys had higher resting HR than controls, due largely to those without a subdiagnosis of conduct disorder. Disruptive boys showed a smaller increment in SC response frequency for task instructions. They did not show a general deficit in phasic SC reactivity but habituated to signal stimuli at a faster rate than did controls. However, their SC response latencies were shorter despite slower motor reaction time. Responsivity variables were similar in boys with and without a subdiagnosis of conduct disorder. The data are not compatible with the hypothesis of low autonomic nervous system (ANS) baselines in disruptive boys but partially suggest low ANS reactivity. They generally support the validity of the disruptive behavior disorder spectrum. Correlations with measures of aggression and impulsivity suggest that individual differences within the spectrum might be more fruitfully described by behavior dimensions than by conventional subdiagnosis.