Grant: Project Grant

Postpartum depression (PPD) affects one in five mothers and can have profound negative effects on infants' abilities to regulate their feelings and behaviours. Emotion regulation is the ability to modify feelings in the service of meeting goals, and problems with it predict emotional, behavioural and school problems later in life. In two small studies, we recently found that treating PPD in mothers could lead to healthy changes in infant brain development, emotion regulation, and mother-infant interactions. However, it is unclear why or how these changes occurred. Larger studies that use multiple methods of measuring infant brain development are urgently needed to understand how treating mothers can improve their infant's emotion regulation. The proposed study will examine how online group cognitive behavioural therapy (CBT), a widely used talking treatment for PPD, affects infant emotion regulation and if changes in mother-infant interactions and/or maternal mood and behaviour following treatment explain these effects. We will recruit 172 mothers with PPD and their infants. 86 mothers with PPD will receive CBT in addition to treatment as usual, and 86 others will receive treatment as usual alone. Infant emotion regulation will be assessed using multiple measures of infant brain development and function, infant observation, and parent reports of infant behaviour. We will also examine changes in mother-infant interactions and maternal mental health (e.g., depression, anxiety) to determine if these explain infant emotion regulation changes occurring in response to maternal PPD treatment. By using a large sample of mothers and multiple measures of infant emotion regulation to examine how commonly used treatments for mothers lead to improved emotion regulation in infants, this study will provide critical evidence on how we can disrupt the transmission of depression and other mental health problems from mothers to their infants.