The Goto Islands, which belong to Nagasaki Prefecture, the westernmost part of Japan, and the islands of the western tip of Nagasaki facing the Goto Sea, are a region with a high incidence of mental disorders such as schizophrenia. It is estimated, in the author's experience, to be five times higher than the national average. Some argue that this is because the islands are a closed, unique world. However, there have been no reports of the islands of Japan being a zone of high incidence of mental illness. Nor do they live on Gotō, only where they are from, that is, where their ancestors - themselves, their parents, their grandparents, or their great-grandparents - were born. 　It could be that some virus, spirochete, or something else is involved. However, the Goto Islands and the islands of the western end of Nagasaki facing the Goto Sea are highly endemic for the retrovirus ATRV (adult T-cell leukemia virus). However, there are other regions in Japan where the adult T-cell leukemia virus (ATLV) is highly endemic, such as the Goto Islands and the islands of the western end of Nagasaki facing the Goto Sea. There are no reports of a high incidence of schizophrenia or other psychiatric disorders in these regions. 　The Goto Islands and the islands of the western tip of Nagasaki facing the Goto Sea contain a large number of genes that are inserted into the genes by retroviruses and predispose to mental illnesses such as schizophrenia.