In this multicenter study, the clinical efficacy of citalopram was investigated in 98 patients with moderate AD/SDAT or VD using a combined double-blind and open technique with placebo and citalopram. Analyses were made for each diagnosis after four weeks of double-blind treatment. Patients with AD/SDAT treated with citalopram showed a significant improvement in emotional bluntness, confusion, irritability, anxiety, fear/panic, depressed mood and restlessness. Those improvements were not found after treatment with placebo. There were no significant improvements in patients with VD. No improvements were recorded in motor or cognitive impairment. Citalopram provoked few and comparatively mild side-effects. None of the changes observed during the double-blind withdrawal period were identified as withdrawal symptoms or rebound phenomena.