Dutch researchers (van Goozen, Matthys, Cohen-Kettenis, Buitelaar, & van Engeland, 2000) tested the hypothesis that children with disruptive behavior disorders (DBD) manifest underarousal of the HP and the ANS, particularly in response to stress. Participants included 26 8-12-year-olds diagnosed with ODD and CD and 26 age- and gender-matched normal controls (NC). The DBD group obtained CBCL Attention Problems, Delinquent Behavior, Aggressive Behavior, and Externalizing scores in the clinical range and TRF Aggressive Behavior and Externalizing scores in the Borderline range.
Physiological measures were taken at baseline and then during a stressful condition in which the youngsters played a computer game against a disparaging “video opponent.” NC and DBD children did not differ in baseline salivary cortisol and both showed decreases in cortisol during the non-stress baseline period. NC subjects increased cortisol secretion during the stress period, but DBD children=s cortisol continued to decline. DBD children had significantly lower heart rates at baseline and a more rapid decline in heart rate during the second half of the stress period than the NC children.
Skin conductance level (SCL) was significantly lower in DBD children at baseline and during both non-stress and stressful conditions. CBCL Aggressive Behavior, Delinquent Behavior, and Externalizing were all significantly correlated (.23-.39) with the magnitude of the children’s aggressive retaliation against the “video opponent.” Furthermore, baseline SCL correlated -.52 to -.67 with CBCL Aggressive Behavior, Delinquent Behavior, and Externalizing scores. SCL, baseline heart rate, and cortisol secretion during stress used together in a logistic regression correctly classified 81% of the participants, with SCL the best predictor. Thus, the children with DBD were not only deviant on CBCL and TRF Aggressive Behavior, Delinquent Behavior, and Externalizing scales, but they also showed a distinctive pattern of HPA and ANS underarousal, especially when placed in a frustrating, aggression-eliciting condition.
The robust correlations between baseline SCL and CBCL/TRF scores indicate an impressive convergence between behavioral and physiological measures.
Reference: van Goozen, S.H.M., Matthys, W., Cohen-Kettenis, P.T., Buitelaar, J.K., & van Engeland, H. (2000). Hypothalamic-Pituitary-Adrenal Axis and Autonomic Nervous System Activity in Disruptive Children and Matched Controls. Journal of American Academy of Child and Adolescent Psychiatry, 39, 11, 1438-1445.