New research published by Dr. Tim Oberlander, CFRI Clinician Scientist and Professor with the Department of Pediatrics, Division of Developmental Pediatrics investigates the complex relationships between pre-birth exposure to selective serotonin reuptake inhibitor (SSRI) antidepressants and thinking and attention skills at six years of age.
SSRIs are a popular class of antidepressants commonly used to treat a mothers’ mood disorder during pregnancy. These medications affect the brain’s level of serotonin, a chemical that plays a critical role in the regulation of mood and attention.
Dr. Oberlander, in collaboration with Dr. Whitney Weikum and Dr. Adele Diamond, followed 64 children from 26 weeks of pregnancy to six years of age. At six years, they conducted genetic testing to identify variations in a gene called SLC6A4 that is associated with the regulation of serotonin. They also assessed mom’s mood and the child’s executive functions (a series of skills that include the ability to focus, be creative and have flexible problem solving skills). These skills help children thrive in the classroom.
Researchers found that while the children’s performance varied depending on whether they were exposed to SSRIs before birth, it was the interaction between the gene variations and mom’s mental health that had the biggest impact. “The impact of prenatal antidepressant exposure is not a simple cause and effect,” says Dr. Oberlander. “When it comes to assessing the long-term impact of SSRI exposure before birth, genes and family life play a powerful role in influencing how a child will be affected. If the mother’s mood was okay, the children performed well,” says Dr. Oberlander. “But when mom was depressed at the time of the study, that’s when we saw a big difference in her child’s executive functions.”
Children of mothers treated with an SSRI during their pregnancy who had at least one short variant for the gene SLC6A4 showed no impairment in executive function, even when their mothers had higher symptoms of depression. In contrast, the performance of children with two long forms of the gene varied depending on the current mood of their mothers.
“When their mothers had few depressive symptoms, these children showed extremely good performance – better than any other group,” said Dr. Oberlander. “But when mothers reported more depressive symptoms, the performance of children with two long forms of the gene was worse than any other group.” “Depression during pregnancy and beyond is a major public health problem for mothers and their children,” Dr. Oberlander added. “Non-treatment is never an option. It is really important that pregnant women discuss all treatment options with their physicians or midwives.”
This research was published online in Frontiers in Cellular Neuroscience in October 2013. Co-authors include Dr. Ruth Grunau, Ursula Brain, Cecil Chau, and Dr. Tom Boyce. These findings build on previous research studying the effects of maternal depression on babies and children from Dr. Oberlander and colleagues with the Developmental Neurosciences & Child Health research cluster at CFRI.
In addition to his role with CFRI, Dr. Oberlander is a Developmental Pediatrician at BC Children’s Hospital and BC Women’s Hospital & Health Centre, and Professor with the UBC Department of Pediatrics. Dr. Weikum is a UBC postdoctoral fellow at CFRI. Dr. Diamond is a CFRI affiliate investigator, professor with the UBC Division of Child & Adolescent Psychiatry and a Canada Research Chair Tier 1.
Dr. Oberlander’s research program is now in its next phase examining how SSRI exposure impacts brain development – including structure, chemical composition and connectivity – using the Child & Family Research Imaging Facility at CFRI.