Overcoming postpartum depression to calm distressed babies with heart rate variability
Mother’s heart rate can calm a baby when her heart rate variability pattern expresses a state of ease to which the baby then naturally synchronizes.
Most know that mothers can calm their distressed baby through a process by which babies ‘tune in’ to the mother, but the biological mechanism and how it is affected by postpartum depression has not been clear until now.
Research just published in the Journal of Psychopathology and Clinical Science shows how mother and baby co-regulate with each other, which turns out to be an excellent illustration of Polyvagal Theory and the power of heart rate variability (HRV) to reveal the functional state of the autonomic nervous system and its role in our capacity to engage with others and our environment.
The authors state:
“Decades of evidence show that mothers provide emotional scaffolding to regulate their infants during moments of distress and that postpartum depression (PPD) can significantly disrupt this process. However, the mechanisms underlying mother-to-infant transmission of regulatory support in real-time are unclear. Examining these mechanisms is critical to understanding how mothers actively shape infant self-regulatory capacity, as well as how psychiatric risk may be transmitted from mother to child..”
Heart Rate Variability—regulating our ability to connect
The authors worked with two sets of mother-infant dyads (pairs), one a normal control group and the other with mothers who had been diagnosed with postpartum depression. Because HRV is known to reflect the emotional state, they monitored it real-time in three phases of interaction: the first play phase, interacting as they normally would; then a still-face phase during which the mothers adopted an expression-less ‘poker-face’, maintaining eye contact with without touching or speaking, which is known to distress babies (and others!); concluding with a reunion phase during which they re-engaged with their distressed infants as in the play phase.
“In 32 healthy mother–infant dyads and 26 dyads affected by PPD (Mage infants = 5.4 months, 40% male), respiratory sinus arrhythmia (RSA)* was acquired simultaneously within dyads on a second-by-second scale during the reunion phase of the still-face task. We examined if the influence of maternal RSA on subsequent infant RSA (measured at the next second) strengthened across the reunion phase.” *RSA = HRV.
This was done twice: at the beginning, then several weeks later after the mothers with PPD had received a course of CBT (cognitive behavioral therapy) that improved their mood.
Mothers with good HRV can lead “the soothing dance”
In the healthy dyads (mothers not suffering from postpartum depression), the mothers’ heart rate variability influenced that of the distressed babies to lead them back to condition of comfort both and baseline and at the follow-up nine weeks later. In the PPD dyads, the same improvement was observed but only in the follow-up session after the mothers’ had been remediated by the course of CBT (as reflected in their improved HRV).
“Among healthy dyads, maternal RSA influenced subsequent decreases in infant RSA, an effect that strengthened across the reunion at both baseline and follow-up visits. In the PPD dyads, this same pattern was also observed, but only at the follow-up visit. Therefore, while mother-to-infant RSA influence patterns differed between healthy and PPD dyads at baseline, the same pattern was observed in both groups at follow-up. This study provides novel evidence for a mechanism that may explain how mothers actively transmit regulatory support to their distressed infants in real-time.”
Interestingly, as reported in a review of this study in Technology Networks Neuroscience News & Research:
“In the healthy control group, the team found that mothers’ heart-rate variability changes influenced those of infants, suggesting that they were leading what Krzeczkowski calls the “soothing dance.”
Conversely, before treatment in the PPD-affected group, it was the infants whose physiological signals led the dance. But after CBT treatment, the PPD mothers’ physiological signalling improved such that they led the interaction, just as the healthy mothers had.”
They further quote lead author John Krzeczkowski, postdoctoral fellow in the Department of Psychology at York University’s Faculty of Health and a trainee at the LaMarsh Centre for Child and Youth Research:
““This study demonstrates empirically, for the first time, that synchronized physiology between mothers and babies plays a role in soothing distressed infants, and that treating PPD with CBT can improve the synchrony patterns and thereby augment mothers’ ability to soothe their distressed babies.
“This study provided important clues into how soothing signals may be transmitted in real time on a moment-to-moment scale between mothers and infants.””
Polyvagal Theory
Polyvagal Theory provides an excellent model that illuminates how the two branches of the vagus nerve (ventral and dorsal) of the parasympathetic nervous system along with the sympathetic nervous system are embedded in HRV signal and reflect the integrity of the neural basis for health, growth, and co-regulating with others; and how an individual in a healthy, ventral vagal state, can function as a wholesome ‘anchor’ for others. Associated with Polyvagal Theory is the Safe and Sound Protocol (SSP) that uses listening to specially filtered music to activate ventral vagal function.
