In a double-blind trial, comprising 96 depressed patients, citalopram was compared with maprotiline. The trial period was 6 weeks with ratings (MADRS, CGI) and side effects recordings taking place at Weeks 0, 1, 2, 4, and 6. Both drugs were administered as a single evening dose, 40 or 60 mg for citalopram, and 75 or 150 mg for maprotiline. MADRS total scores and CGI scores showed a highly significant reduction in both groups with no significant difference between them, whether the groups were considered as a whole or whether they were subdivided into endogenously/non-endogenously depressed or melancholic/non-melancholic patients. Side effects were not significantly different, but the maprotiline group showed more anticholinergic side effects, whereas the citalopram group showed more nausea, increased sweating and headache. Two patients on maprotiline were withdrawn because of side effects (hypotension and somnolence in the one case; tremor and insomnia in the other). One patient in each group was withdrawn because of increased transaminases, the citalopram-treated patient having increased values, however, already at baseline. Apart from this, no cardiovascular side effects and no pathological laboratory values related to treatment were observed. The authors conclude that citalopram is a safe antidepressant drug and as effective as maprotiline.