EPIDEMIOLOGY OF PRESENILE ALZHEIMERS-DISEASE IN SCOTLAND (1974-88) .2. EXPOSURES TO POSSIBLE RISK-FACTORS

Background and Method. We related geographical variation of 'probable' presenile Alzheimer's disease (AD PSD) to exposures to possible risk factors for AD PSD and vascular dementia (VaD) and to geographical dif ferences in survival times after presentation with AD PSD. Results. We found that an ecological measure of socio-economic deprivation was re lated to VaD but not to AD PSD. Among men with AD PSD and VaD, specifi c occupations conveyed no altered risk but having fathers who were coa l miners was associated with AD PSD and VaD in offspring. Increased pa ternal age was associated with AD PSD but only in men. These factors a cted independently of one another and did not distinguish between geog raphical areas of high and low incidence. Conclusions. The length of s urvival after presentation with AD PSD distinguished between these are as, and when migration between these areas was taken into account, a p lausible multifactorial model of the harmful effects of environment em erged, which acted independently of risk factors acting earlier in lif e.