According to the hypothesis of a biochemical disorder, we found that schizophrenic patients show a modified reaction to stress. We have checked 668 male schizophrenic patients and found 18 ulcers (2.69%) this is contrasted by the average incidence of ulcers at the rate of 10%.12 of the 18 probands had preliminary serious somatic lesions. We came to the conslusion that the hypothalamic stress response is altered: Schizophrenic patients and the normal population show a significant difference to the incidence of gastric ulcers.