The 2-mg dexamethasone suppression test in differentiating major depression with psychosis from schizophrenia

The 2-mg dexamethasone suppression test (DST), performed in a drug-free acute exacerbation phase of illness shortly after admission, differentiated between major depression with psychosis and stringently diagnosed chronic schizophrenia. This has practical significance because effective drug treatment in each diagnostic group is different. Nonsuppression was seen in all six newly admitted patients in a drug-free acute exacerbation phase of illness with major depression with psychosis. Suppression was seen in all 20 newly admitted chronic schizophrenic patients in a drug-free acute exacerbation phase of illness, with the exception of two very agitated patients with mildly elevated 11 p.m. cortisol samples. Studies are briefly reviewed and suggest that nonsuppression with 1-mg DST may occur in the absence of pituitary-adrenal disinhibition and in the acute exacerbation phase of some chronic schizophrenic patients.