Mental deficiency is a heterogenous condition resulting from a variety of etiological factors. Even though in a considerable proportion of cases of mental deficiency we may have some insight into the underlying pathology and the cause, many other instances of this condition remain completely obscure.
A working classification of mental deficiency has been much in need for both practical and research purposes. Penrose8 (1954) analyzed this aspect thoroughly and found that almost all suggested divisions of previous investigators were dichotomic, irrespective of what basis of classification was chosen. The following are the more interesting examples which he cites: "congenital" vs. "acquired"; "endogenous" vs. "exogenous"; "hereditary" vs. "acquired"; "pathological" vs. "subcultural." The last subdivision, which was presented by Lewis6 in 1933, is the most comprehensive, and it will be used in this communication as a starting point in discussion, although in a modified version and wording.
It is suggested,
DEKABAN AS. Mental Deficiency: Recessive Transmission to All Children by Parents Similarly Affected. AMA Arch NeurPsych. 1958;79(2):123–131. doi:10.1001/archneurpsyc.1958.02340020003001
Customize your JAMA Network experience by selecting one or more topics from the list below.