The influence of pretreatment respiratory sinus arrhythmia dimensions on trauma-focused cognitive behavioral therapy outcomes: Findings from a randomized controlled feasibility trial.

Child maltreatment is associated with respiratory sinus arrhythmia (RSA) dysregulation, a physiological indicator of emotion regulation that predicts elevated posttraumatic stress disorder (PTSD) symptoms and may be a mechanism of action for exposure-based therapies, such as trauma-focused cognitive behavioral therapy (TF-CBT). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT for improving emotion regulation following maltreatment. The current study reports findings from a randomized controlled feasibility trial (N = 33; M_age = 11.79 years, SD = 3.08; 63.6% White; 66.7% female) that measured youths' resting RSA, RSA reactivity, and RSA recovery in response to a pretreatment laboratory challenge. We tested whether (a) lower pretreatment resting RSA was associated with blunted RSA during the challenge; (b) either of the pretreatment RSA dimensions predicted more severe pretreatment PTSD symptoms; and (c) either of the pretreatment RSA dimensions predicted less severe posttreatment PTSD symptoms and, as an exploratory aim, whether this was moderated by treatment group (i.e., TF-CBT vs. TF-CBT + AAT). Results from multiple linear regression indicated that, after controlling for pretreatment symptom severity, there was a large effect size for higher resting RSA predicting less severe caregiver-reported posttreatment PTSD symptoms, β = -.52, p = .058, and higher RSA during recovery predicting less severe child-reported posttreatment PTSD symptoms, β = -.70, p = .056, although these findings were not significant. These preliminary results offer important insights for future studies to investigate how the ability to regulate RSA informs which children need additional support to benefit from psychotherapeutic treatment.