A variation in brain chemistry between the sexes may make women more likely to suffer from emotional stress than men, new research has claimed.
Scientists in the US say that women, who have higher rates of depression, post-traumatic stress disorder and other anxiety problems, are more sensitive to low levels of a key stress hormone.
The study focused on how a group of rats responded to a swim stress test. It found that females had neurons which were more sensitive to corticotropin-releasing factor (CRF), a hormone which organises stress responses in the mammals.
Research leader Dr Rita Valentino, from The Children's Hospital of Philadelphia, told online journal Molecular Psychiatry that the same signalling pathway is known to play a role in human psychiatric conditions, although, to date, no proven biological difference had been established as producing different stress responses between men and women.
Dr Valentino said: "This may help to explain why women are twice as vulnerable as men to stress-related disorders. Pharmacology researchers investigating CRF antagonists (blocking agents) as drug treatments for depression may need to take into account gender differences at the molecular level."