Senile dementia of the Alzheimer type in the Lundby Study. I. A prospective, epidemiological study of incidence and risk during the 15 years 1957-1972.

In spite of the great impact of senile dementia of the Alzheimer type (SDAT) on society, far too little is known about its epidemiology. In this study of a total, normal population from a geographically delimited area in Sweden, Lundby, 2612 persons were examined in 1957 by one psychiatrist (Hagnell). In 1972 the same population was reexamined irrespective of domicile. The incidence and risk of contracting SDAT during the 15 years were calculated. No cases of SDAT were diagnosed before the age of 60 years. The lifetime risk was for men 25.7% and for women 26.2%. When only the very severely impaired were taken into account, the figures were 14.5% in men and 14.6% in women.