Elevated Cortisol Level and Cortisol/DHEAS Ratio in Schizophrenia as Revealed by Low-Dose Dexamethasone Suppression Test

Earlier studies have used the dexamethasone (DEX) suppression test (DST) to investigate the hypothalamic- pituitary-adrenal (HPA) function in schizophrenia, although the findings are controversial. Recently there has been an increased interest in the role of dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) in HPA axis function. Several studies have investigated basal DHEA(S) levels and cortisol/DHEA(S) ratios in schizophrenia patients, while no attempts have been made to investigate DHEA(S) level in response to the DEX administration. We aimed to compare the post- DEX cortisol and DHEAS levels and the cortisol/DHEAS ratio between schizophrenia patients and healthy controls. Here we administered the DST to 43 patients with schizophrenia and 37 age- and sex-matched healthy controls. Plasma cortisol levels, serum DHEAS levels, and cortisol/DHEAS ratio after administration of 0.5 mg of DEX were compared between the two groups. Schizophrenia patients showed significantly higher cortisol level and cortisol/DHEAS ratio than controls, while DHEAS levels were not significantly different between groups. These results suggest that besides the cortisol level, cortisol/DHEAS ratio as assessed with the DST might reflect abnormal HPA axis function in schizophrenia.