The effect of sodium valproate on serum cortisol levels in healthy subjects and depressed patients.

Abstract

In nine healthy subjects the i.v. injection of 800 mg of the GABA-transaminase inhibitor sodium valproate (SV) was able to suppress serum cortisol significantly when compared to saline. Three and a half hours after the administration of SV, serum cortisol was reduced to less than 50% of the basal value in each of the subjects. Among 17 depressed patients serum cortisol was reduced to less than 50% of basal value 3 1/2 h after SV in only two patients. No difference was found between nine patients with endogenous depression and eight with non-endogenous depression. The dexamethasone suppression test was abnormal in four out of 17 patients. These four patients had endogenous depression, and also an abnormal response to SV. A positive correlation was found between the effect of SV on serum cortisol, and age (r = 0.55), but not between the percentual decrease of serum cortisol and the severity of depression. The effect of SV on serum cortisol was significantly less pronounced in depressed patients than in controls but no difference was found between patients with endogenous and non-endogenous depression.