There may be a biological reason why depression and other stress-related psychiatric disorders are more common among women compared to men. Studying stress signaling systems in animal brains, neuroscience researchers found that females are more sensitive to low levels of an important stress hormone and less able to adapt to high levels than males.
"This is the first evidence for sex differences in how neurotransmitter receptors traffic signals," said study leader Rita J. Valentino, Ph.D., a behavioral neuroscientist at The Children's Hospital of Philadelphia. "Although more research is certainly necessary to determine whether this translates to humans, this may help to explain why women are twice as vulnerable as men to stress-related disorders."
The research appears online today in Molecular Psychiatry. The study's first author is Debra A. Bangasser, Ph.D., a fellow in Valentino's laboratory.
It has long been recognized that women have a higher incidence of depression, post-traumatic stress disorder, and other anxiety disorders, said Valentino, but underlying biological mechanisms for that difference have been unknown. Her research focuses on corticotropin-releasing factor (CRF), a hormone that organizes stress responses in mammals.