For all her good intentions, science-writer Henig's aim to demythologize senility misfires. True, she convinces the reader that the dementias of aging are diseases, not natural consequences of advancing years. But in elaborating the theme she pursues so many theories, reviews so many controversial therapies, and quotes so indiscriminately (from both the eminent and the not-so-eminent) that the reader is likely to be baffled: what real research advances hive been made? what hope does lie ahead? Henig creditably enumerates the many conditions affecting older adults that can mimic dementia--drug effects, depression, hormone imbalances, malnutrition, to name some. She also describes the major cause of senile dementia, Alzheimer's disease, in great detail. Still, her prose is occasionally muddled or inconsistent, and all too often freighted with as-we-shall-see-in-another-chapter phrases. One long chapter describing in graphic detail the daily life of an Alzheimer's-disease patient, and his kin, is a particular worry: though the reader is warned that patients with Alzheimer's disease vary in symptoms, in behavior, and in the progression of the disease, the case history presented is unnecessarily frightening and depressing; not all Alzheimer's-disease patients are as irascible and restless as the man depicted, a danger to himself and to his family. There is indeed a growing need to educate the general public and involved professionals about the care and treatment of elderly patients; but this education must draw a distinction between the changes in metabolism, the minor memory losses, and the other impairments that may accompany normal aging and, on the other hand, the changes that result from neurological disorders. Henig wants to convey that message, but it comes out skewed, overwritten and, sadly, not very positive.