Sensitivity and specificity of 1 and 2 mg dexamethasone suppression tests

Sensitivity and specificity rates for 1 and 2 mg dexamethasone suppression tests (DSTs) are compared in 119 psychiatric inpatients diagnosed by DSM-III criteria. No differences are apparent between 1 and 2 mg groups. Moreover, combining a variety of affective disorders does not change the rates from those obtained using major depression alone. These data do not support a previous study which suggested that, compared to a 2 mg DST, a 1 mg test increases sensitivity without diminishing specificity. Nonsuppression appears to identify a subgroup of patients that cuts across several DSM-III categories.