Female stress: Brain chemistry link

Women may be more prone to emotional stress than men because of their brain chemistry, scientists have said.
A study has shown that females are more sensitive to low levels of a key stress hormone.
Although the research was conducted on rats, the same signalling pathway is known to play a role in human psychiatric conditions.
"This may help to explain why women are twice as vulnerable as men to stress-related disorders," said US study leader Dr Rita Valentino, from the Children's Hospital of Philadelphia.
Women have higher rates of depression, post-traumatic stress disorder and other anxiety problems than men.
However no-one has yet been able to pinpoint a biological reason for the difference.
The new research, published in the online journal Molecular Psychiatry, focuses on a hormone that organises stress responses in mammals called corticotropin-releasing factor (CRF).
A study of rats undergoing a swim stress test showed female animals had neurons that were more sensitive to CRF. The scientists also found that stressed male rats adapted by making themselves less responsive to the hormone, but females did not.
Dr Valentino pointed out that other mechanisms also played a role in human stress responses. But it was already known that CRF regulation was disrupted in people with stress-related psychiatric disorders. Since much of the previous animal research on stress used only male rodents, important sex differences may have gone undetected, she added.
"Pharmacology researchers investigating CRF antagonists (blocking agents) as drug treatments for depression may need to take into account gender differences at the molecular level," said Dr Valentino.