Infants whose mothers underwent therapy for postpartum depression (PPD) continued to show improvements in their emotional regulation months after the treatment was over, says new Brock research.

The research team, led by John Krzeczkowski, examined data they gathered in a past study with Professor Ryan Van Lieshout at McMaster University that found Cognitive Behavioural Therapy (CBT), a form of psychotherapy, had positive effects on both mother and baby following its completion.

“In any early intervention study that reports benefits, the next question is often, do these benefits last?” says Krzeczkowski. “This is a critical question, since the whole point of early interventions is to set children on a new, more adaptive developmental trajectory and away from risk for psychopathology.”

The Assistant Professor of Health Sciences and his team sought to answer the question of whether the benefits of therapy would be seen in infants months after CBT treatment for their mothers stopped.

CBT seeks to change the thoughts, attitudes and beliefs of people experiencing difficult situations such as depression.

During their first year of life, infants begin to develop the skill of emotional regulation, which entails using specific behaviours to control the intensity, interpretation and expression of emotions.

The ability to regulate emotions is key to achieving goals, maintaining relationships and experiencing overall health and well-being.

By observing the infant’s brain, nervous system and motor activities, researchers can detect a range of behaviours and responses connected to emotional regulation. These include approach, withdrawal, avoidance, responding flexibly to changes in the environment and expressing positive and negative emotions.

Mothers who are sensitive to their baby’s cues and can respond appropriately — such as providing comfort in times of distress — are helping the infant’s brain develop adaptive behaviours to regulate their emotions, says Krzeczkowski.

Maternal depression and anxiety may make mothers less responsive to their infants’ emotional states. Over time, this reduced bonding impacts the development of the infants’ brain and nervous systems involved in emotional regulation, making them vulnerable to psychiatric conditions and emotional challenges down the road, he says.

In this latest study, Krzeczkowski and his team analyzed data gathered from their earlier research conducted several years ago.

The team had recruited 35 mothers diagnosed with major depressive disorder and 33 mothers without a diagnosis of depression as a comparison group. The participants’ infants were less than a year old.

Mothers with the depression diagnosis attended a nine-week CBT program. Infants’ brain waves and heart rate were tested and their emotion expression behaviours were assessed, while depression, bonding and emotion regulation were examined in mothers before and after treatment.

The infants were then brought in three months later and underwent the same testing and assessment as what occurred immediately after the therapy.

The team found the infants had retained improvements in their emotional regulation, as shown through brain-wave activity thought to reflect more positive emotions, greater heart rate variability indicating a better ability to deal with emotional challenges and more smiling and laughing, says Krzeczkowski.

“The combination of changes in the mother — the improvement in mood, a better ability to recognize their baby’s cues, the agency and confidence to navigate through moments of distress — following CBT treatment are all really important things that may alter their infant’s brain towards more adaptive outcomes,” he says.

Krzeczkowski says he hopes the research contributes to efforts aimed at making treatments for postpartum depression more widely available.

The team’s study, “Adaptive changes in infant emotion regulation persist three months following birthing parent receipt of cognitive behavioral therapy for postpartum depression,” is posted online and is scheduled to be published next month in the Journal of Affective Disorders.