Abstract
OBJECTIVE: There is support for altered parasympathetic (PNS) and sympathetic (SNS) functioning among children with disruptive behavior disorders (DBD) which may underlie impairments in both emotion regulation (ER) and executive functioning (EF). This study examined the extent to which cardiac autonomic balance (CAB), a composite index that integrates the relative influences of the PNS and SNS on the heart, differentiates young typically developing (TD) children and those with a DBD. METHOD: Participants included 245 young children (72% boys, M (age) = 5.44 years; 82% Latinx; 50% TD). Indexes of PNS (i.e., respiratory sinus arrhythmia [RSA]) and sympathetic (i.e., pre-ejection period [PEP]) reactivity were collected during a baseline task along with six other lab tasks measuring ER and EF. CAB was computed using the following formula: CAB = RSAz - ( - PEPz) with higher positive scores reflective of greater reliance on PNS input. RESULTS: No difference in resting/baseline CAB was found among the groups. On the other hand, children with DBDs had lower and negative CAB reactivity scores across 4 out of the 6 tasks relative to the TD group which had positive CAB reactivity scores (Cohen's d range = -0.27 to -0.38). CONCLUSIONS: Children with DBDs' negative CAB values indicate a physiological profile of greater SNS reactivity while children in the TD group's positive CAB values indicate a physiological profile of greater PNS reactivity. A lower and negative CAB reactivity profile may be a physiological indicator that contributes to underlying impairments in both EF and ER among children with DBD.