Heredity of Constitutional Mental Disorders.

Abstract

Examines whether each type of mental disorder is inherited as a unit character, or whether they result from abnormalities of the cytoplasm of the germ cell or chromosomes, conditioning mental disorders in the offspring which may present the same, or other clinical manifestations. iFeeble-mindedness, follows Mendelian law, and is due to the absence of a single Mendelian factor. Most analyses that have been made of the feeble-minded have been scientifically insufficient; despite this, the results hold good. Mongolian imbecility, formerly asserted to be non-inheritable, was investigated by Herrman, who found that it usually revealed a neurotic condition in both parents. Brandeis found amaurotic family idiocy to be a simple Mendelian recessive. The epilepsies, are also inherited as a simple Mendelism defect (Weaks; Lundborg). Flood and Collins have provided at least partial conformation of the conclusion that both feeblemindedness and epilepsy are caused by the same defect. Dementia praecox, too, is a simple Mendelian recessive (Riedin; Cannon & Rosanoff; Rosanoff & Orr; Jolly & Witterman). Temperament was studied by the author, who concluded that it is probably a Mendelian dominant. The formulae for expressing the possibilities in the inheritance of different temperaments, and their combinations have been provided. Hunting's Chorea is inherited as a dominant disease. Criminality may be due to several causes and its inheritance will follow according to the cause and type. Consanguinity per se is not responsible for mental disorders; however, if both parents carry some recessive defect, the inherited taint will appear in at least one quarter of the children. From Psych Bulletin 18:01:00090. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1920 American Psychological Association.