An account of a clinical double-blind research project with an adjustingand a evaluation-period wherein pipotiazine was compared with chloropromazine. 48 Patients suffering from a chronic hospitalization-syndrom took part in this project which was particularly aiming at the activating effect of pipotiazine. The anti-psychotic effect of pipotiazine proved to be of the same category as that of chloropromazine, there were however insufficient indications to show a specific activating effect of pipotiazine. Regarding the activating as well as the anti-psychotic effects there were no statistically significant differences to be found between pipotiazine and chloropromazine. More side-effects of an extrapyramidal kind were to be seen when using pipotiazine than in the case of chloropromazine.