Broad implications for respiratory sinus arrhythmia development: associations with childhood symptoms of psychopathology in a community sample.

Replicating the group-based developmental trajectory methodology from our prior study (Patriquin, Lorenzi, Scarpa, & Bell. 2014. Developmental Psychobiology, 56, 317-326), the current study examines the development of baseline respiratory sinus arrhythmia (RSA) across a new, larger cohort of typically developing children at 5, 10, 24, 36, and 48 months of age and examines the trajectory relationship with symptoms of childhood psychopathology. Group-based developmental trajectory modeling replicated our prior findings of a two-group model fit: a "High RSA" and "Low RSA" group. The "Low RSA" group, which demonstrated lower baseline RSA across all time points, had significantly more childhood problems at 48 months, namely increased withdrawal, aggressive behavior, pervasive developmental problems, and oppositional defiant problems. All participants for whom there were developmental or autism spectrum concerns (n = 6; based on maternal report at 48 months) were allocated to the Low RSA trajectory group. These results suggest that consistent developmental trajectories of RSA may point to protective factors (i.e., high RSA) against developing symptoms of childhood psychopathology.