Published: February 23, 2011
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine.
A common gene variant was associated with a nearly doubled likelihood of posttraumatic stress disorder (PTSD) in at-risk urban women -- but not in otherwise similar men, researchers said.
The affected gene encodes a receptor protein believed to mediate stress responses, and is also modulated by estrogen signalling, according to Kerry Ressler, MD, PhD, of Emory University in Atlanta, reporting in the Feb. 24 issue of Nature.
Heavily traumatized civilian women with two copies of a specific single nucleotide polymorphism (SNP) in the ADCYAP1R1 gene were more likely to show PTSD with an odds ratio of 1.66 (95% CI 1.32 to 2.09) relative to similar women without the condition, Kessler and colleagues found.
The same SNP -- called rs2267735, substituting a cytosine base for a guanine -- in men exposed to fearful situations showed no association with PTSD, the researchers also found (OR 0.95, 95% CI 0.71 to 1.27).
The authors did point out, however, that women are more likely to develop PTSD than men and this discrepancy may relate to the modulation of the receptor pathway by estrogen.
Nearly 40% of women in the study had the CC genotype, carrying two copies of the risk-associated SNP.
In that group, an average of 15 PTSD symptoms were identified clinically, compared with 11 in individuals with the CG or GG genotypes (P<0.05).
About one-third of the 763 women in the study were diagnosed with PTSD.
Other researchers contacted by MedPage Today and ABC News said the results were promising but needed replication in larger and different samples.
"This study was done on chronically ill patients, those with both chronic medical and chronic psychological co-morbidities, so it's difficult to know if the signaling is from PTSD or from their co-morbidities," said Charles Marmar, MD, of NYU Langone Medical Center in New York City, in an e-mail. "There's a need for replication in a younger, healthier population with more recent trauma exposure."
Judith A. Myers-Walls, PhD, of Purdue University in West Lafayette, Ind., also noted that the methodology left some questions unanswered.
"The data were collected after the PTSD symptoms were identified, so it is not clear whether the stress reaction itself created the changes in physiology or they existed before the exposure to the stressful situation," she said in an email. FULL STORY
Who is old enough to remember that PTSD was invented (made up from thin air) to describe attitude problems of men returning from the damnable Vietnam war in the 1970's only to find themselves HATED for having gone?
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