REM sleep in depression is influenced by ethnicity

The influence of ethnicity on the manifestation of EEG sleep changes in dep ression was studied in 95 patients (21 African-Americans [AA], 17 Asians [A S], 37 Caucasians [C] and 20 Hispanics [H]) with unipolar major depression. Subjects were studied twice for 2 consecutive nights. On the second night of each 2-night session, placebo or scopolamine (1.5 mu g/kg, IM, at 23.00 h) was administered. On the baseline (placebo) night, sleep architecture, s leep continuity and rapid eye movement (REM) sleep variables were generally comparable among the groups. However, REM sleep was less in AA and AS subj ects than in C and H subjects. Furthermore, the distribution of REM sleep o ver the course of the night in AA and AS subjects differed significantly fr om that in the C and H groups. Although scopolamine significantly affected sleep continuity and REM sleep measures, no significant differential effect s of scopolamine were observed. Because many antidepressants suppress REM s leep, the differences in baseline REM sleep observed might be related to th e greater sensitivity of some ethnic-minority depressed patients to pharmac otherapy. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.