Five female inpatients with major depression (melancholic type, DMS-III-R) were treated with the beta-adrenergic agonist clenbuterol for three weeks, with doses ranging from 100 micrograms to 150 micrograms. Remission of depressive symptomatology during treatment was observed in only one patient. All patients complained of side effects, especially tremor, agitation and restlessness. The sleep EEG showed no consistent effects on sleep parameters, including REM latency and percentage of REM sleep. Thus, the impact of clenbuterol on sleep clearly differs from that of most classical antidepressants. Regarding the lack of therapeutic efficacy, the data are compatible with the hypothesis of a relationship between REM sleep suppression and an antidepressant drug effect. Despite the small sample size, it can be concluded that clenbuterol is not likely to be a promising alternative to proven antidepressants in the treatment of major depression.