DEPRESSIVE PSYCHOMOTOR DISTURBANCE, CORTISOL, AND DEXAMETHASONE

We examine the dexamethasone suppression test as a biological correlat e of melancholia as defined by the CORE system, a scale for rating obj ective signs of psychomotor disturbance. Postdexamethasone cortisol co ncentrations and rates of nonsuppression were higher in CORE, Newcastl e, and DSM-III-R defined melancholic groups. These differences, howeve r, were no longer significant after partialling out the combined effec ts of age, dexamethasone, and basal cortisol concentrations, There was a significant correlation between the CORE (but not the Newcastle) sc ale and 8:00 AM postdexamethasone cortisol levels, which persisted aft er partialling out those same three covariates. Dexamethasone concentr ations themselves were lower in CORE- and Newcastle-defined melancholi cs, though these were no longer significant after covarying for cortis ol concentrations. Dexamethasone levels were also significantly invers ely correlated with CORE and Newcastle scales, A significant correlati on between CORE (but not Newcastle) scores and dexamethasone levels at 4:00 PM persisted after partialling out the effects of age and cortis ol. These findings indicate an intriguing relationship between the COR E system as a dimensional construct for rating psychomotor disturbance , and both postdexamethasone cortisol and dexamethasone concentrations . (C) 1996 Society of Biological Pyschiatry