Background: The hypothalamic-pituitary-adrenal axis and the catecholaminergic system are involved in the pathophysiology of post-traumatic stress disorder (PTSD). This was a prospective and longitudinal study of neuroendocrine physiology in children with PTSD following a motor vehicle accident (MVA).
Methods: Sixty children aged 7-18 were studied immediately after an MVA and 1 and 6 months later. Fasting morning plasma catecholamine and serum cortisol concentrations were measured. Salivary cortisol concentrations were measured serially five times daily to examine circadian variation in all three assessments. Values were compared between those who did (PTSD) or did not develop PTSD (non-PTSD) after the trauma and a control group at months 1 and 6.
Results: Twenty-three of the children had PTSD at the 1-month and 9 children at the 6-month evaluations. 1) Plasma noradrenaline concentrations were higher in the PTSD group than in the other two groups at both months 1 and 6 (p = .001 and p = .001, respectively). Additionally, the PTSD patients presented with significantly higher salivary cortisol concentrations at 18.00 (p = .03) and 21.00 (p = .04) at month 1.2) Eight children suffering from PTSD at both months 1 and 6 had significantly elevated plasma noradrenaline concentrations at month 6 compared with those at month 1 and at baseline and to the other two groups (within subjects: p < .001; between subjects: p = .005). The initially elevated evening salivary cortisol concentrations in this group normalized at month 6.
Conclusions: This progressive divergence of noradrenaline and cortisol concentrations over time might underlie the natural history and pathophysiology of PTSD.