The dexamethasone suppression test (DST) was administered to 28 subjects who met DSM-III criteria for chronic schizophrenia and shared similar environments. Samples were assayed for both plasma cortisol and dexamethasone levels. After controlling for other factors, the mean postdexamethasone cortisol level (MPDC) was correlated with the patients' score on the Scale for the Assessment of Negative Symptoms (SANS). A significant relationship emerged between these 2 parameters, suggesting that the social deterioration seen in chronic schizophrenia is at least partly related to a biological disease process as reflected by the DST. The importance of quantifying the level of dexamethasone in the DST is discussed.