A double-blind study was carried out in 62 hospital out-patients suffering from mild to moderate depression to investigate the efficacy and tolerance of fluvoxamine given as a single daily dose or in divided doses. Patients were allocated at random to receive 100 mg fluvoxamine either as a single daytime dose, a single night-time dose or as 50 mg twice daily over a period of 6 weeks after a 1 week wash-out period on placebo. Patients were assessed using the Hamilton and Montgomery Asberg depression rating scales and the Clinical Global Impression scale before and during treatment. All three dosage regimens produced significant improvement and no significant difference was found in antidepressive effect between the groups. However, patients receiving a single night-time dose experienced fewer side-effects leading to drop-out before the end of the study than in the other two groups.