Serum postdexamethasone prolactin measures in depressive patients and control subjects

Recently, some researchers noted significant positive relationships between postdexamethasone serum cortisol and prolactin levels, whilst endogenous depressives exhibited a significantly lower suppression of prolactin by dexamethasone than non-endogenous patients or normal controls. To ascertain the extent of prolactin responses to dexamethasone in severely depressed patients, we measured 8 a.m. pre- and postdexamethasone prolactin levels in 104 depressed and 42 normal subjects. Serum cortisol levels were also determined in depressed patients before and after dexamethasone administration. We found a significant suppressive effect of dexamethasone on prolactin levels. There were no significant differences either in pre- or postdexamethasone prolactin, or in actual dexamethasone-induced decrements in prolactin between normal controls, melancholics, simple major or minor depressed subjects. We have not found any significant relationships between cortisol and prolactin, either under baseline or postdexamethasone conditions.