Serial CSF corticotropin-releasing hormone levels and adrenocortical activity in combat veterans with posttraumatic stress disorder

Objective: The authors sought to carefully test, by using a technique of co ntinuous CSF sampling, the hypothesis that basal elevations in CSF corticot ropin-releasing hormone (CRH) concentrations exist in patients with posttra umatic stress disorder (PTSD). They also sought to assess the relationship among PTSD symptoms, adrenocortical activity, and CSF CRH levels. Method: C SF was withdrawn by means of a flexible, indwelling subarachnoid catheter o ver a 6-hour period, and hourly CSF concentrations of CRH were determined f or 11 well-characterized combat veterans with PTSD and 12 matched normal vo lunteers. Twenty-four-hour urinary-free cortisol excretion was also determi ned. PTSD and depressive symptoms were correlated with the neuroendocrine d ata. Results: Mean CSF CRH levels were significantly greater in PTSD patien ts than in normal subjects (55.2 [SD=16.4] versus 42.3 pg/ml [SD=15.6]). No correlation was found between CSF CRH concentrations and PTSD symptoms. Wh ile there was no significant difference between groups in 24-hour urinary-f ree cortisol excretion, the correlation between 24-hour urinary-free cortis ol excretion and PTSD symptoms was negative and significant. Conclusions: B y using a serial CSF sampling technique, the authors found high basal CSF C RH concentrations and normal 24-hour urinary-free cortisol excretion in com bat veterans with PTSD, a combination that appears to be unique among psych iatric conditions studied to date.