The effects of the antidepressant trazodone on clinical state and on EEG sleep in eight outpatients with a major depressive disorder were investigated in a single blind study. A medication period of 5 weeks was preceded and followed by one week placebo treatment. Five subjects showed a positive treatment response. Trazodone did not influence sleep continuity and slow wave sleep, but did suppress REM sleep significantly. A significant increase of REM sleep latency was also found. These results are in contrast with earlier reports on trazodone's effects on EEG sleep but are in accordance with the general finding that antidepressants influence REM sleep characteristics without necessarily affecting sleep continuity.