Epigenetics and mental health
Estonia-born Mari Sild came to Concordia to join the team of Linda Booij, associate professor in the Department of Psychology and a member of the Centre for Clinical Research in Health.
With a background in genetic engineering, Sild is here to study the effects of childhood adversity on human brain development.
Early life adversity is known to be a major risk factor for later-life psychiatric disorders including depression. However, the mechanisms underlying such associations are not yet well understood.
“There is now emerging evidence that early-life adverse events may leave a lasting influence on brain function — through so-called ‘epigenetic’ modifications that alter gene expression — without changing the DNA sequence,” Sild explains.
“This in turn can result in vulnerability for mental disorders in later life.”
Sild became increasingly interested in neuroscience and mental health after completing her MSc at Aarhus University in Denmark under the supervision of professors Bjørn Nexø and Suresh Rattan.
Her work focused on the molecular basis of human aging. She then moved to Montreal to pursue her PhD with Edward Ruthazer at the Montreal Neurological Institute.
During her PhD, Sild worked extensively on the functions of a lesser-explored cell group in the brain called “glial cells” that traditionally had been considered passive bystanders in the brain.
“We and others have found that glia are far from being passive, actively communicating with neurons and other glia, and participating in neural network formation and maintenance,” she says.
“Consequently, they are likely to be very much implicated in mood, cognition and the prevention of mental health problems.”
During her postdoctoral fellowship, Sild is working within a multidisciplinary team of experts from Concordia, CHU Sainte-Justine and McGill. Their objective is to measure, for the first time, levels of an epigenetic modifier, histone deacetylase (HDAC), in the human brain in relation to childhood adversity. HDAC is a protein suspected of contributing to a range of psychiatric disorders.
The project might yield important results for designing novel interventions and treatments for the long-term psychiatric consequences of childhood adversity.
“Mental health is still quite under-researched globally,” Sild says.
“One in six people will struggle with depression in their life and the medication available doesn’t always work. We need to better understand the mechanisms of psychiatric disorders to find better solutions, including non-pharmaceutical ones.”