"The findings suggest that there may be persistent differences in the stress response in some trauma-exposed people, even if they do not exhibit PTSD or depression or both, and even if their trauma was years in the past," said Barbara Ganzel, a lecturer in human development in Cornell's College of Human Ecology.
Ganzel led a team of Cornell researchers that assessed a group of women before and after they took their medical admissions tests (MCATs), a stressful experience for most people. Measuring levels of a stress hormone in saliva (cortisol), they found that women who had experienced trauma earlier in life but who did not have PTSD or major depression had lower levels cortisol leading up to and after the MCAT exam.
In addition, they found that the women who had experienced trauma kept a negative mood after the test, compared with other women, whose moods lifted significantly after the exams.
Ganzel suspects that the stress response system in these women have compensated or changed over time. The trauma-exposed women showed lower rather than higher levels of cortisol, Ganzel theorized, because "stress initially boosts cortisol output but after the stressor is over, cortisol falls below normal. These data suggest that, in some people, it may fall below normal and stay there, or that it develops a chronic tendency to dip lower than normal under stress."
MEDICA.de; Source: Cornell University