Paranoid Schizophrenia in a Mongoloid Defective: Some Theoretical Considerations Derived from an Unusual Case

Abstract

In the past thirty years a great deal of attention has been paid to the problems of differentiating mental deficiency from psychosis, and recognizing the distorting effects of mental defect and deprivation upon supervening mental illnesses. The incidence of psychotic syndromes in mental deficiency hospitals has been variously estimated as 5 per cent (Greene 1933), 8 per cent (Vanuxem 1935), and 11 per cent (James 1939), while a survey made by Hackbush (1935) on a very large number of patients on the waiting list for admission to mental deficiency hospitals, suggested a figure of 10 per cent. James considered that three-quarters of his psychotic group were schizophrenic, and Bergman et al. (1951) agreed that schizophrenic illnesses were very common in mental defectives. Whereas the incidence of schizophrenia in the general population is 0.85 per cent (Mayer-Gross et al. 1954), it occurs as much as nine times more frequently in certain mentally defective groups.