N. ARAI, Y. SHIBATAH, . YAMAMOTJO., MURATA,
K. MUKOYAMYA., ISHIKAWAM, . OKADAH, . NOGUHCI,
M, MISU, S. MIYAMOTOan d T. MARUYAMA
During July, 1958, the authors made census for Ukishima, Ibaraki prefecture in Japan. The results were as follows:
1) On account of the frequent population movement, the rate of inbreeding was relatively low (3.75% of the population) and this. rate was nearly equal to the average of Japan.
2) The rate of endogenous mental disorders was not high (0.5% of the population) and especially there was no manic-depressive psychosis, including hereditary factor.
3) The rate of schizophrenia was somewhat high and there was recognized many patients who recovered well from the illness. we recognized more the selection in this schizophrenic group.
4) Both the rate of inbreeding and incidence of endogenous mental disorders, among those who migrated from various cities, showed no specialities. However, the higher rate of various mental disorders was recognized as compared with other districts