The effect of diagnosis and age on the DST: a metaanalytic approach

The authors present new data on the results of the pretreatment Dexamethasone Suppression Test (DST) in 164 drug-free inpatients, as well as on the effects of age on postdexamethasone cortisol values. Nonsuppression rates were 18% in schizophrenic patients (n = 44), versus 46% in patients with a major depression (n = 56). In addition, a significant correlation was found between age and the 4:00 PM postdexamethasone cortisol value among the depressed patients (r = 0.33). The authors then applied a metaanalysis to summarize 25 other studies that have addressed the schizophrenia/major depression dichotomy as it relates to the DST outcome. Nonsuppression rates were consistently different in schizophrenic patients (19%) when compared to patients with a major depression (51%) or normal controls (7%). These differences were highly significant as measured by the Mantel-Haenszel chi-square statistic. A metaanalysis applied to a series of correlations obtained from 14 other studies reporting an age/postdexamethasone cortisol relationship in affective patients indicated a modest, but significant correlation (r = 0.24) in a total of 1284 patients (p less than 1 x 10(-8)).