ABSTRACT
This chapter reviews evidence for genetic factors in the development of dementia, because studies have consistently shown an increased risk for first-degree relatives of aged patients with Alzheimer-type dementia. It examines the diagnosis of dementia is based on behavioral criteria, most notably the cognitive markers of memory loss and general intellectual deterioration, the possibility of identifying a behavioral phenotype for dementia-prone individuals is explored, using data from a 20-year longitudinal study. Cytogenetic studies have provided an additional method for investigating genetic determinants in senile dementia. Some three million elderly Americans are afflicted with dementia today, and as the aged are the fastest growing segment of our population, increasing numbers of persons are likely to be affected. The current clinical consensus that dementia strikes indiscriminately relative to premorbid capacities and characteristics merely underscore our ignorance about the disease. Integrated psychobiological investigations of dementia are needed to address the issue of prediction, especially those using a family study methodology.
