Hipotalamoptuiter-adrenal axis dysfunctions (HPA) are thought to play an important role in PTSD. HPA axis responds to stress with secretion of glucocorticoids (i.e., cortisol), which is vital in maintaining biological homeostasis and adaptation (allostasis) to chronic stress. In this study, we aimed that the relationship between PTSD symptoms and serum cortisol levels were investigated.

Forty-eight (N=48) males inpatients with PTSD diagnosed according to the DSM-IV criteria were enrolled to the study. The mean±SD of their age was 26.6±5.8 years. The rates of patients were related with combat and other traumatic events: 83.3% and 16.7% respectively. The mean duration±SD of their illness was 17.9±20.1 months (median 8 months). The severity of PTSD symptoms was evaluated by clinician administered PTSD scale (CAPS) I, II and impact of the event scale (IES). Morning and evening serum cortisol levels were obtained before and after the applying dexamethasone suppression test.

The rate of comorbidity in PTSD was 66.6%. Co-morbidity increases the severity of PTSD, but the serum cortisol levels were not associated with comorbidity. The negative correlations were determined between the basal (morning) serum cortisol levels and severity of symptoms CAPS II intrusive and avoidance symptoms (r=-0.31, p=0.04), (r=-0.30, p=0.05); evening serum cortisol level and IES score (r=-0.30, p=0.05); morning serum cortisol after administration of dexamethasone and CAPS I intrusive symptom severity (r=-0.37, p=0.01).

We found that serum cortisol levels were negatively related to intrusive and avoidance symptoms of PTSD. These data show specificity of abnormal HPA axis dysfunctions in PTSD.