Vagal rebound during resolution of tearful crying among depressed and nondepressed individuals.

Respiratory sinus arrhythmia (RSA) is an index of the vagal control of heart rate that is associated with emotion regulatory capacity. To examine RSA in depressed and nondepressed participants in the context of an emotion-regulatory challenge, we presented a sad film to induce crying, a behavior associated with heightened parasympathetic activation. We predicted that nondepressed persons who cried would show elevations in RSA during the onset and the resolution of crying. By contrast, we predicted that depressed individuals who cried would fail to exhibit increased RSA over the course of their crying episodes. As hypothesized, nondepressed participants exhibited RSA increases that accompanied the resolution of tearful crying, consistent with a homeostatic function for crying, whereas depressed subjects who cried did not exhibit increased RSA. Results suggest that the physiological self-regulatory mechanisms invoked by crying are compromised in depression.