Babies born to depressed moms show altered brain connectivity

About one in five women experience some form of depression during pregnancy, with poorly understood effects on the fetus. Prenatal depression is linked to behavioural and developmental issues in children as well as an increased risk for depression as young adults. But how prenatal depression leads to these changes remains unclear.

UCalgary researcher Dr. Catherine Lebel, PhD, a member of the Hotchkiss Brain Institute, The Mathison Centre and the Alberta Children's Hospital Research Institute, is helping understand what may be happening in the developing brains of these children. The research team has shown that young children whose mothers experienced more numerous symptoms of depression in pregnancy have altered connectivity in brain pathways involved in emotion. These structural changes can be related to increased hyperactivity and aggression in boys.

The research is based on diffusion magnetic resonance imaging, an imaging technique that probes the strength of structural connections between brain regions. The findings are published in The Journal of Neuroscience.

“The results help us understand how depression can have multigenerational impacts, and speaks to the importance of helping mothers who may be experiencing depression during pregnancy,” says Lebel, an associate professor at the Cumming School of Medicine. She holds the Canada Research Chair in Paediatric Neuroimaging.

Lebel and her team studied 54 Calgary mothers and their children. They were enrolled from the ongoing, prospective study called the Alberta Pregnancy Outcomes and Nutrition study. Mothers answered a survey about their depression symptoms at several points during their pregnancy.

Their children were followed after birth and undertook an MRI scan at the Alberta Children’s Hospital at around age four. As well, the children’s behaviour was assessed within six months of their MRI scan.

The team found a significant reduction in structural brain connectivity between the amygdala, a structure essential for emotional processing, and the frontal cortex. Altered connectivity between the amygdala and frontal cortex is associated with disruptive behaviours and vulnerability to depression.

The first author on the study, Dr. Rebecca Hay, MD, stresses the importance of recognition of depression and intervention in prenatal health. “These results suggest complex associations between the prenatal environment and children’s brain development, and may help us to understand why children of depressed mothers are more vulnerable to depression themselves,” says Hay, a resident physician in paediatrics and recent Cumming School of Medicine graduate.

Current study looks at stress during pandemic

Lebel and her research team are currently trying to understand how stress and mental health are affecting pregnant women during the COVID-19 pandemic. She is examining how factors such as social supports might mitigate stress, and how this may influence pregnancy and birth outcomes.

If you are interested, you can get involved here in the Pregnancy During the COVID-19 Pandemic study at the University of Calgary. So far, approximately 7,500 women from across Canada are enrolled and supplying information through questionnaires.

“It is critical to appropriately recognize and treat prenatal maternal mental health problems, both for the mothers and to improve child outcomes,” says Lebel. “Now more than ever, with increased stress, anxiety and depression during the COVID-19 pandemic, we should do more to support mothers to positively impact the health of their children.”

Lebel is an associate professor in the Department of Radiology at the Cumming School of Medicine, adjunct associate professor in the Werklund School of Education and a member of The Mathison Centre for Mental Health Research & Education, Owerko Centre at ACHRI, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute.

The study was funded by the Canadian Institute of Health Research, Alberta Innovates - Health Solutions, the Alberta Children's Hospital Foundation, the National Institute of Environmental Health Sciences, the Mach-Gaensslen Foundation, and an Eyes High University of Calgary Postdoctoral Scholar.

Led by the Hotchkiss Brain Institute, Brain and Mental Health is one of six research strategies guiding the University of Calgary toward its Eyes High goals. The strategy provides a unifying direction for brain and mental health research at the university.