Prediction of postdexamethasone cortisol levels by serum sodium levels in patients with major depression.

The authors analyzed the dexamethasone suppression test (DST) results of 54 patients with major depressive disorder in relation to their pre-DST levels of cholesterol, sodium, potassium, and blood glucose, which are thought to have adrenocorticotrophic links. Discriminant analysis revealed that sodium alone was a significant predictor of nonsuppression. Validation of the predictive power of sodium could minimize the need for DST administration.