Age and gender effects on the diagnostic power of the DST

Among 365 major and 158 minor depressive inpatients, the dexamethasone suppression test (DST) yielded an overall diagnostic sensitivity of 50%, a specificity of 85%, and a confidence level of 88%. Age was significantly correlated with the post-dexamethasone cortisol levels in the whole sample (r = 0.11; P less than 0.01); however, this low relationship disappeared when all subgroups defined by gender or diagnostic were considered. Gender did not appear to influence DST results; however, among the patients between 30 and 39 years, the diagnostic performance of the DST was significantly lower among female as compared to male patients, suggesting possible interferences with endocrine variables.