The dexamethasone suppression test in residual schizophrenia with depression.

The authors administered the Carroll rating scale for depression to 100 patients with residual schizophrenia and found that 41 were also depressed. Of these 41 patients, 23 were given a dexamethasone suppression test; 7 (31%) failed to suppress cortisol. A matched control group, i.e., 23 patients with residual schizophrenia but without depression, suppressed cortisol normally after taking dexamethasone. The authors found no clinical differences between depressed patients with normal DST results and depressed patients with abnormal DST results.