Relationship between sibship size and neurotic symptoms of anxiety, hypochondriasis and depression in Japanese neurotic children and adolescents.

Two hundred and sixty-eight Japanese aged 19 or below were studied retrospectively from their medical records to determine the relationship between the sibship size (number of siblings in the family) and the appearance of symptoms of anxiety, hypochondriasis and depression during the time period I (1955 + 1960 + 1965) and the time period II (1970 + 1975 + 1978). The results showed that only sons and either sex of a large sibship size (4 or more) possessed these three symptoms to a larger extent than only daughters and either sex of a medium sibship size (2 or 3) during both time periods. These three adult-type neurotic symptoms were thought to be manifested among the children and adolescents who communicated primarily with adults and/or those who were required by their parents to exhibit adult-type behavior whether in traditional or in modern Japanese families.