Mothers and birthing parents with postpartum depression (PPD) have better odds of recovering when they receive therapy from other mothers who've had the same experience, according to new research from McMaster University.

Researchers at the university worked with nearly 200 mothers over a year and a half, and found those receiving cognitive behavioural therapy (CBT) from their peers were 11 times more likely to experience remission of their major depressive disorder.

is a structured, problem-focused and goal-oriented form of psychotherapy that helps people learn to identify and reshape how their thoughts, attitudes and beliefs affect their emotional and behavioural reactions.

The study's findings could have implications for a large segment of the population, since PPD and its associated symptoms affect up to 20 per cent of new mothers and birthing parents, according to lead author Ryan Van Lieshout.

"Postpartum depression is very common, and it can affect up to one in five birthing parents now," Van Lieshout, who is also Canada Research Chair in perinatal mental health, told CTVNews.ca in a phone interview on Wednesday. "But even though we have universally available health care here in Canada, as few as one in 10 (people) with postpartum depression can actually get evidence-based care."

Left untreated, PPD increases the risk of future depressive episodes, family problems and cognitive, emotional and behavioural problems in the child.

One of the reasons why so few people get help for PPD, Van Lieshout said, is that there simply aren't enough mental health care professionals available to meet the demand for effective treatments like CBT. He said another problem is that sometimes birthing parents with postpartum depression don't feel like treatment will be effective for them unless it's delivered by someone who has been through PPD themselves.

"By training individuals recovering from postpartum depression to deliver the treatment, we're hoping that we can reduce some of those barriers by providing (birthing parents) with access to group facilitators who've gone through this before," Van Lieshout said, "and also by task shifting delivery of the treatments to people who are outside of the health-care system to hopefully increase the capacity to treat all of those individuals who have postpartum depression but who haven't been getting treated."

Van Lieshout and his team recruited 183 mothers from across Ontario between August 2020 and February 2022 and randomly assigned them to two groups.

One group would receive their regular treatment of choice outside of the study, plus nine weeks of group CBT delivered online from peers who had recovered from PPD themselves.The other group, a control group, would only receive their regular treatment of choice. After all the relevant data had been gathered at the end of each session, the participants in the control group were also offered peer-delivered group CBT, as a courtesy.

Participants who received peer-led CBT as part of the study experienced clinically significant improvements in postpartum depression and anxiety, as well as better social support, less anxiety about their child and improvements in their infant's temperament.

Sixty-four per cent of participants in the peer-led treatment group met the criteria for major depressive disorder at time of enrollment. After participating in the nine-week program, only six per cent met the criteria. On the other hand, 43 per cent of participants in the control group met the criteria for major depressive disorder after nine weeks, compared to 66 per cent at the time of enrollment. For the first group, these changes lasted up to five months after participants started treatment.

Lee-Ann Mosselman-Clarke participated as a peer facilitator in about a dozen of the nine-week group CBT sessions and described the experience as a "massive passion project." Mosselman-Clarke has two children – 11 and nine years old – and sought treatment for postpartum depression proactively during her second pregnancy, after struggling following the birth of her first child.

"I had anxiety, postpartum anxiety and postpartum rage, which I didn't know was a thing. I felt angry all the time and I didn't talk about it because, you know, you're new mom," she said in a phone interview with CTVNews.ca.

She wishes she'd had the same support she was able to offer other new mothers when she'd had her first child. At the time, she said, no one around her discussed postpartum depression, including in her stoic Dutch family.

"I think being able to talk openly and honestly about it is more helpful than trying to keep it all in," she said.

Before the launch of the study, Mosselman-Clarke and other peer facilitators participated in a three-day training program for individuals with no prior formal psychiatric training and observed the nine-week intervention delivered by experts in a hospital setting. Facilitators then delivered the intervention online in pairs. They were paid $30 per hour for their work, though Van Lieshout said many had offered to do the work for free.

Van Lieshout had reason to believe the model would work even before launching the study, since previous research he'd conducted showed group CBT for PPD delivered by public health nurses with little to no previous psychiatric training led to significant improvements in depression and anxiety. He's already got plans for a follow-up study.

"The next study, we're going to see if we can train the peers not only to deliver the intervention, but also to provide sort of oversight and supervision to each other," he said.

"So that we can try to make try to make the intervention more sustainable and more appealing to policymakers and funders so that we can so that it can be scaled more broadly."

METHODOLOGY

Results are based on a study conducted from Aug. 25, 2020 to Feb. 22, 2022 among 183 adults in Ontario. Participants had an infant under 12 months old, were fluent in English and scored higher than 10 on the Edinburgh Postnatal Depression Scale.

The study used a single-blind parallel-group RCT design. Participants were randomized in a 1:1 ratio to the online peer-delivered nine-week intervention plus treatment as usual or to receive treatment as usual. Depression, anxiety, social support, mother-infant bonding, and infant temperament were assessed at baseline and nine weeks later.

Outcomes were assessed in the experimental group three months post-intervention to assess stability.