According to research published in Nature Communications, a team of Université Laval scientists may have identified why chronic depression affects men and women differently.
The researchers analyzed the brains of mice who died from depression and observed differences in distinct areas of the brain for each sex.
They also discovered a possible biomarker for depression in women.
Caroline Ménard, lead author, professor, Faculty of Medicine, Université Laval, and researcher, CERVO Brain Research Centre, states that men and women experience depression in very different ways. The disorder is twice as frequent in women, the symptoms differ, and the response to pharmaceuticals differs from that of males.
How Depression acts in the Brain According to Genders
Caroline Ménard’s team previously showed that chronic social stress in male mice compromised the blood-brain barrier, separating the brain from peripheral blood circulation.
These alterations were seen in the nucleus accumbens, a portion of the brain related to reward and emotion regulation, due to the lack of a specific protein claudin-5.
The researchers discovered the same phenomenon in the brains of males who died due to depression.
Professor Ménard said that the prefrontal brain regulates mood, anxiety, and self-perception. This portion of the brain was unaffected in highly stressed male mice and male patients with depression.
According to these findings, persistent stress affects the brain barrier differently depending on gender.
The researchers uncovered a blood signature associated with brain barrier health as they dug deeper.
Soluble E-selectin, the marker, is an inflammatory molecule identified in increased amounts in the blood of anxious female mice.
It is also found in the blood of women suffering from depression, though not in males.
There Are Better Ways to Spot Depression Than through Questionnaires
Ménard said that depression is still evaluated using questionnaires and there is room for improvement. He stated that the experiment group is the first to demonstrate the significance of neurovascular health in depression and propose soluble E-selectin as a depression biomarker. It has the potential to screen and diagnose depression. It might also be used to assess the efficacy of existing or developing therapies.
However, large-cohort clinical investigations will be required first to demonstrate the biomarker’s reliability.
These discoveries would not have been achieved without the contributions of individuals and families to the Douglas Bell Canada Brain Bank and the Signature Bank in Montréal.
