Sympathetic- and parasympathetic-linked cardiac function and prediction of externalizing behavior, emotion regulation, and prosocial behavior among preschoolers treated for ADHD

Abstract

Objective: To evaluate measures of cardiac activity and reactivity as prospective biomarkers of treatment response to an empirically supported behavioral intervention for attention-deficit/hyperactivity disorder (ADHD).

Method: Cardiac preejection period (PEP), an index of sympathetic-linked cardiac activity, and respiratory sinus arrhythmia (RSA), an index of parasympathetic-linked cardiac activity, were assessed among 99 preschool children (ages 4-6 years) with ADHD both at rest and in response to behavioral challenge, before participants and their parents completed 1 of 2 versions of the Incredible Years parent and child interventions.

Results: Main effects of PEP activity and reactivity and of RSA activity and reactivity were found. Although samplewide improvements in behavior were observed at posttreatment, those who exhibited lengthened cardiac PEP at rest and reduced PEP reactivity to incentives scored higher on measures of conduct problems and aggression both before and after treatment. In contrast, children who exhibited lower baseline RSA and greater RSA withdrawal scored lower on prosocial behavior before and after treatment. Finally, children who exhibited greater RSA withdrawal scored lower on emotion regulation before and after treatment.

Conclusions: We discuss these findings in terms of (a) individual differences in underlying neurobiological systems subserving appetitive (i.e., approach) motivation, emotion regulation, and social affiliation and (b) the need to develop more intensive interventions targeting neurobiologically vulnerable children.

Conflict of interest statement

Carolyn Webster-Stratton has disclosed a potential financial conflict of interest because she disseminates these treatments and stands to gain from favorable reports. Because of this, she has voluntarily agreed to distance herself from certain critical research activities, including recruitment, consenting, primary data handling, and data analysis. The University of Washington has approved these arrangements.

Figures

Figure 1

Eyberg Child Behavior Inventory scores at pre- to post-treatment for children who scored > 1.0 SD below the sample mean on PEP reactivity (solid line) and for children who scored > 1.0 SD above the sample median on PEP reactivity (dashed line). Although both groups improved, individual differences in problem behavior were maintained.

Figure 2

Conners’ Rating Scale—Revised inattention scale scores at pre- to post-treatment for children who scored > 1.0 SD below the sample mean on RSA withdrawal (solid line) and for children who scored > 1.0 SD above the sample median on RSA withdrawal (dashed line). Although greater RSA withdrawal was associated with more attention problems at pre treatment, this difference disappeared by post treatment.