Women, but not men, with post-traumatic stress disorder have high blood levels of a stress-related hormone, new research shows.
The hormone - pituitary adenylate cyclase-activating polypeptide (PACAP) - is known to affect central nervous system activity, metabolism, blood pressure, pain sensitivity and immune function.
In the new study, published in Nature, researchers assessed 64 people with post-traumatic stress disorder (PTSD) and found that symptom scores were five times higher among women with above-average PACAP levels than among women with below-average PACAP levels.
Different triggers for men, women
The team also found that, due to genetic variations, PTSD may be triggered by different biological pathways in women and men.
The finding that PACAP levels are an indicator of PTSD symptoms may lead to new ways to diagnose and treat PTSD and other anxiety disorders, the study authors noted.
"Few biological markers have been available for PTSD or for psychiatric diseases in general. These results give us a new window into the biology of PTSD," said first author Dr Kerry Ressler, an associate professor of psychiatry and behavioural sciences at Emory University School of Medicine.
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