Dementias — A Growing Social and Medical Problem

The expectation of life has risen constantly in most of the industrialized countries in the last 80 years. It was shown that the over 65 year-old US-population has grown from 3 millions in 1900 to more than 27 millions in 1984. About 6% of these persons suffered from Alzheimer’s disease. This group of illnesses increases with age — about 20–25% of people aged 85 years will be affected — actually more than 2 millions; in 65 years time this number will have increased to 16 million persons (G.D. Cohen 1986). B.E. Tomlinson (1986) pointed out that a world-wide collaboration and the search of subgroups with detailed analysis of cases — early onset or late onset — is required. Among the multiple aetiological factors, dementia caused by ischaemic lesions must be separated from dementias of other origin. “Our thinking about Alzheimer’s disease is too restricted if we assume that chemical and neuropathological findings and aetiology have to be identical and consistent from case to case” (Tomlinson). Davison (1982) pointed out that “functional deficits are greater than they would be expected from the neuropathological changes”.