The real cause of depression may lie in just two brain cell types, scientists say |
In a major scientific breakthrough, scientists have identified two specific types of brain cells linked to depression for the first time, offering a clearer biological understanding of the disorder. Researchers at McGill University and the Douglas Institute discovered that neurons and microglia, two key cell types responsible for regulating emotion and inflammation, show significant genetic changes in people suffering from depression. Using advanced single-cell genomic mapping of post-mortem brain tissue, the team found that these cells exhibit disrupted gene activity, paving the way for more precise and effective treatments for one of the world’s most common mental health conditions.
How scientists identified the depression-linked cells
The researchers conducted their study using rare post-mortem brain tissue from the Douglas-Bell Canada Brain Bank, one of the few collections globally with samples from individuals who lived with psychiatric conditions. Through single-cell genomic analysis, they examined thousands of neurons and microglia cells to track how their gene expression differed in people with and without depression. The study, published in Nature Genetics, revealed that excitatory neurons responsible for mood and stress regulation, as well as microglia, immune cells managing inflammation in the brain, showed clear molecular alterations linked to depressive symptoms.
A biological foundation for depression
The discovery reinforces the view that depression is not merely emotional or psychological but deeply rooted in biological processes within the brain. Senior author Dr. Gustavo Turecki explained that the research maps both gene activity and DNA regulation, providing unprecedented insight into which brain cells are disrupted and why. “It gives us a much clearer picture of where disruptions are happening and which cells are involved,” Turecki said. The findings support years of neuroscience suggesting that depression involves measurable changes in brain chemistry and structure, not just mood or environmental triggers.
Implications for future treatments
By pinpointing the exact brain cells affected, scientists now have a more defined target for developing next-generation antidepressants. Rather than broadly altering brain chemistry, future treatments could focus on restoring balance in these specific neurons and microglia, reducing side effects and improving efficacy. Understanding how these cells communicate and regulate emotion and inflammation could also help researchers predict who is most at risk of depression and how to intervene early.
What comes next
The McGill team plans to further explore how the cellular changes they identified influence overall brain function and emotional regulation. They hope that studying these cell types in greater detail will lead to therapies that act directly on the disrupted biological pathways. The study not only deepens scientific understanding of depression but also offers hope for millions affected by it worldwide.
