Dexamethasone suppression test in several major mental illness

Recently, Dexamethasone Suppression Test (DST) seemes to be an effective tool for association in the diagnosis of endogenous depression. Our research is to evaluate the sensitivity and specificity of DST in endogenous depression. From July 1983 to June 1984, we collected 32 cases with the diagnosis of endogenous depression (including 11 bipolar depression and 21 major depression), 25 schizophrenia (including 9 with depression and 16 without depression), 12 borderline disorder, 10 dysthymic disorder and 10 voluntary normal persons. The sensitivity of DST for endogenous depression was 65.6%, which was significantly higher than that of schizophrenia group (40%), borderline disorder group (33.3%) and the control group (10%) (including dysthymic disorder and voluntary normal person) (x²=16.19, df=3, p<0.001). However, the specificity of DST were 60%, 66.7% and 90%, respectively for the compared groups mentioned above. Therefore, DST is good only for discriminating the endogenous depression from the dysthymic disorder and from normal person. To differentiate the other mental illnesses (e.g. schizophrenia, boderline disorder) from endogenous depression, the complete history and clinical symptoms are necessary and essential.