A systematic literature review of respiratory sinus arrhythmia response to psychotherapy in pediatric samples.

The present review synthesizes research examining changes in parasympathetic biomarkers of self-regulation (i.e., respiratory sinus arrhythmia [RSA] activity) over the course of intervention or prevention programs in pediatric samples. Based on a preregistered protocol (PROSPERO: CRD42024550670), PubMed and PsycINFO databases were searched until July 1, 2025 to identify 13 peer-reviewed, empirical studies reporting indices of RSA activity in samples of infants, children, and adolescents participating in psychotherapy treatment programs. Study quality was evaluated using design-specific tools from the NHLBI and ROBINS-I, and results were synthesized narratively given differences in study design, intervention type, and RSA measurement. Seven studies examined immediate pre-post changes in baseline RSA, and all seven reported increases on average. All four studies that assessed RSA at follow-up showed maintenance of the posttreatment pattern. Seven studies assessed RSA reactivity; six observed pre-post change, though the direction varied. Following treatment for externalizing disorders, youth generally showed increased RSA withdrawal, whereas youth generally showed reduced RSA withdrawal or greater stability following treatment for internalizing disorders. Four studies examined RSA across multiple treatment sessions, and three reported within-treatment shifts. Correspondence between RSA change and psychosocial symptom reduction was found in most studies testing this link, though patterns of association varied across samples. Thus, baseline RSA and RSA reactivity may respond to treatment, although patterns of change vary based on symptom presentation. Limitations of this body of literature include small sample sizes and methodological heterogeneity. Findings are considered in relation to models of self-regulation and build on previous reviews of altered autonomic functioning in pediatric samples with dysregulation.