BACKGROUND

The present study evaluated the accumulated changes in hair cortisol levels of patients with posttraumatic stress disorder (PTSD) attributed to the 2008 Wenchuan earthquake in China.

METHODS

Sixty-four female adolescents from two townships who experienced the earthquake were recruited 7 months after the disaster, including 32 subjects with PTSD (PTSD group) and 32 subjects without PTSD (non-PTSD group). Twenty matched adolescents were recruited from an area that was not affected significantly by the earthquake as the control group. Hair cortisol concentrations were measured by the electrochemiluminescence immunoassay in each 3-cm segment of hair sample from the scalp.

RESULTS

There was no significant difference at the baseline hair cortisol level in the three groups before the traumatic event (p > .6). Hair cortisol levels changed over time and differed among groups (p = .0042). The hair cortisol levels among the PTSD and non-PTSD subjects were elevated, suggesting increasing levels in response to stress. However, these two groups differed in their response. The non-PTSD subjects showed a significantly higher cortisol level than the PTSD group between month 2 and month 4 (p = .0137) and also between month 5 and month 7 (p = .0438) after the traumatic event.

CONCLUSIONS

This study revealed a blunted response curve to the disaster among PTSD subjects compared with subjects without PTSD. These findings suggest that hair cortisol level could be used to assess the integrated hypothalamic-pituitary-adrenal activity over a period of months after traumatic events and be used to serve as a biomarker in patients with PTSD.