EFFECTS OF LOW-DOSE DEXAMETHASONE ON SLEEP EEG PATTERNS, PLASMA-CORTISOL, AND THE TSH RESPONSE TO TRH IN MAJOR DEPRESSION

Dexamethasone (DEX) (0.5 mg, P.O.) and placebo were administered at 23 00 h in randomized design to 19 patients with major depression and the effects on the sleep electroencephalogram (EEG) were studied. In addi tion, the thyroid stimulating hormone (TSH) response to thyrotropin re leasing hormone (TRH) and basal plasma cortisol concentrations were as sessed the following morning. DEX did not affect sleep architecture or continuity variables, including rapid eye movement (REM) latency, REM activity and REM density. Similarly, DEX did not significantly influe nce the TSH response to TRH (DELTA(max) TSH). In contrast, plasma cort isol concentrations were significantly suppressed by DEX. The results indicate that, as opposed to higher dosages of glucocorticoids, 0.5 mg DEX had minimal effects on the sleep EEG or DELTA(max) TSH in depress ed patients.