This 6-week, open-label, multicenter study evaluated the efficacy and safety of quetiapine in combination with citalopram in adult patients (n=25) with ICD-10/DSM-IV unipolar psychotic depression. The primary endpoint was change from baseline to Week 6 in the Hamilton Depression Rating Scale (HAM-D-21) score. Secondary endpoints were change from baseline to Week 6 in the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression (CGI) Scale scores. Spontaneously reported adverse events (AEs), the Simpson Angus Scale (SAS), and the Udvalg for Kliniske Undersogelser (UKU) side effects rating scale scores were recorded. Patients' average age was 51.4 years and baseline weight was 72.6 kg. Quetiapine (50-750 mg/day, mean dose+/-SD: 303+/-118 mg/day), in combination with citalopram (20-60 mg/day, mean dose+/-SD: 34+/-12 mg/day), provided significant improvements in depression. Mean (+/- SD) HAM-D-21 was reduced to 13.25+/-10.87 at Week 6 from a baseline value of 31.21+/-5.18. Significant improvement of psychotic symptoms (mean+/-SD) was indicated by the decrease from baseline (59.25+/-6.60) to Week 6 (35.25+/-15.60) in BPRS scores. No serious AEs occurred. The mean change in weight was +2.1 kg. Mean (+/- SD) weight at visit 1 was 72.72 (+/-16.34) kg and mean (SD) weight at visit 4 was 74.79 (+/-18.69) kg. Quetiapine in combination with citalopram appears to be effective and is well tolerated in the treatment of unipolar psychotic depression. Further studies of larger, double-blind, parallel-group design are warranted to confirm these findings.