Elevated baseline and postdexamethasone cortisol levels. A reflection of severity or endogeneity?

This study investigated whether elevated baseline and postdexamethasone cortisol levels were more strongly related to severity of depression or presence of endogenous symptoms. In 43 inpatients with major depressive disorder, a positive correlation was found between the total score on the Hamilton Rating Scale for Depression and 8.00 a.m. and 4.00 p.m. baseline and 8.00 a.m. and 4.00 p.m. postdexamethasone cortisol levels. Only the 8.00 a.m. postdexamethasone cortisol level was significantly correlated with the number of Research Diagnostic Criteria (RDC) endogenous items present. Despite a statistically significant relationship between severity and endogeneity, our results suggest elevated baseline and postdexamethasone cortisol levels may be more closely related to severity of depression, rather than the presence of a cluster of symptoms referred to as endogenous.