For eight weeks 30 psychotic patients with a healthy cardiovascular system received 3 X 50 mg 1-[3-(10,11-dihydro=5H-dibenz[b,f]-azepin-5-yl]-propyl]-4-piperidiono-piperdine-4-carboxamide dihydrochloride-monohydrate (carpipramine) per day with a placebo phase of three weeks either previous to the medication of succeeding it. In addition there was a group of similar patients without any medication. From this study it was concluded that carpipramide has no depressive effect on the cardiovascular system. The differences in blood pressure and heart rate after the change from medication to placebo indicate a certain vegetative lability in this phase. In the ECG, no irregularities of the atrioventricular and intraventricular conduction and its repolarisation in form of a lengthening were observed; only the WPW-syndrome noticed with one patient might be related to the medication since it occurred at the end of the three weeks during which carpipramine had been administered.