Approximately one in ten pregnant women experience depression. Poorly treated, this serious mental health condition affects the mother’s health and quality of life and can have lifelong consequences for the unborn baby such as behaviour problems, learning disabilities and a higher risk of diabetes and obesity later in life. Anti-depressant medications can successfully treat depression and other mood disorders for many women, but these medications have their own risks; there are still unanswered questions about how these drugs affect a baby’s development.
Improving care – and finding answers – for pregnant women who experience depression and their babies, is a key goal for Dr. Tim Oberlander and his colleagues and at BC Children’s Hospital. In a new study, they’ve used state-of-the-art MRI scans to study the effects of SSRI anti-depressants on the developing brain. Their work could eventually provide valuable information about the long-term consequences of taking these drugs during pregnancy and contribute to new approaches for managing depression that give both mothers and babies the best possible chance for a long-term health.
A recent study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, led by Dr. Tim Oberlander, Ms. Naama Rotem-Kohavi and Dr. Lynne Williams, reported that newborns who were exposed to selective serotonin reuptake inhibitors (SSRIs), a class of anti-depressant drugs, during pregnancy showed changes in brain activity in areas of the brain believed to be associated with early auditory processing and language development. The research was conducted at BC Children’s 3TMRI, and is the first paper reporting on neonatal outcomes using this world-class facility.
Dr. Oberlander and his colleagues want expectant families to know that this is an exciting and important scientific finding, but not one that should influence treatment decisions.
“Untreated mood disorders have significant health risks for both mothers and babies,” says Dr. Oberlander. “When a pregnant woman is struggling with her mental health, non-treatment is never an option. Women should work with their caregivers to explore medications and other treatment options and find a choice that works for them.”
Previous research has shown an association between SSRI exposure and increased risk of premature birth, low birth weight and changes in the baby’s behaviour and development. However, scientists remain unsure if these changes are solely the result of SSRI exposure, or if depression contributes to them as well.
In this study, researchers worked to overcome this challenge; to distinguish between changes caused by SSRIs and changes associated with depression. Researchers recruited pregnant woman who had depression and were taking SSRIs, pregnant women who had depression and were not taking medication, and pregnant women without mood disorders. In total, 84 women participated in the study.
Researchers used surveys to assess the women’s moods during pregnancy. Six days after the babies were born they returned to hospital to undergo a resting-state functional magnetic resonance imaging (fMRI) scan in the 3TMRI at BC Children’s Hospital, one of very few facilities in Canada able to scan newborns without sedation. As opposed to a task-based fMRI, which measures brain activity while the subject completes a specific task or activity, the resting-state fMRI evaluates how different brain regions interact with each other based on changes in blood flow while the subject is at rest. This makes it possible to measure brain activity in newborn infants while they are sleeping.
Researchers found that newborns who’d been exposed to SSRIs during pregnancy had more spontaneous blood oxygen level dependent (BOLD) activity in areas related to the primary auditory cortex. This part of the brain is involved in processing sound and plays an important role in language development. Determining if and how these increased levels of brain activity impact the development of children who were exposed to SSRIs before birth will require more research.
“Will these children have advanced language development as they grow? This is still an open question, and we plan to continue to follow these children to find out,” says Rotem-Kohavi.
This adds to previous research showing SSRI exposure changes developmental patterns related to language perception. In a 2012 study that Dr. Oberlander co-authored with lead author Dr. Janet Werker, a Professor in the UBC Department of Psychology, and Postdoctoral Fellow Dr. Whitney Weikum, researchers tested fetuses at 36 weeks gestation and then at six and ten months of age and found those exposed to SSRIs as fetuses were advanced in their ability to discriminate between vowels and consents and showed accelerated closure of a critical “window” for distinguishing between their native language and other languages.
“Our latest findings are very intriguing when placed in the context of this previous research,” says Dr. Oberlander. “In our 2012 study we saw evidence of a connection between SSRI exposure and language perception development and now we are able to see supporting evidence of function inside the brain.”
Eventually, research like this may help doctors to use existing medications to manage depression during pregnancy in new ways that don’t affect the baby’s development or create new treatments. It could also help clinicians provide families with better information about the potential long-term health impacts of taking SSRIs during pregnancy.
However, researchers want to be clear that this science is still at an early stage and more research will need to be done to understand the full implications of this study.
“It is important for families to realize that this study shows an association between SSRI exposure and changes in brain activity, but it does not show that SSRI exposure causes those changes,” says Dr. Williams.
For women currently struggling with mental health during pregnancy, the good news is there are many resources available to help. Expectant mothers experiencing mood disorders or other mental health conditions should talk to their care providers to learn more about their options for treatment. More information about mental health during pregnancy is available from BC Children’s Hospital Reproductive Mental Health program and the Pacific Postpartum Support Society.
“Poor maternal mental health during pregnancy is a major public health issue,” says Dr. Oberlander. “I encourage any mothers who are struggling to reach out and work with care providers to find a treatment that works for them and their families.”
This research was supported by BC Children’s Hospital Foundation and Canadian Institutes of Health Research.
The 3TMRI facility is supported by BC Children’s hospital Foundation, Canada Foundation for Innovation and BC Knowledge Development Fund.
