In a previous communication,1 based on a study of 890 patients with psychasthenia in the private practice of Dr. Hugh T. Patrick, I presented a statistical formulation of the hereditary factors in this disorder. In a second communication2 I presented data showing that patients with psychasthenia have a hereditary endowment different from that of persons in good mental health. The question naturally follows: Do patients with schizophrenia and with manic-depressive psychosis present differences in heredity from that of patients with psychasthenia? Does the more benign psychasthenia arise from the same or from a different hereditary subsoil than do manic-depressive psychosis and schizophrenia? The present study is concerned with this question.
Data regarding the hereditary factors in manic-depressive psychosis have been made available by Sünner,3 for the more malignant institutional type, and by myself,4 for the more benign extramural type seen in private practice. Data regarding hereditary