BACKGROUND: Cognitive changes during the preclinical phase of @entity195 ( @entity195 ) @entity303 have been characterized among European Americans (EAs), but studies of preclinical changes among @entity3004 ( @entity3004 ) are notably absent. METHODS: Preclinical changes in cognition before the development of @entity195 and mild @entity73 over a period of 18 years were examined using change points in a biracial sample of 2,125 older adults. RESULTS: Of 2,125 @entity1 , 442 (21%) developed @entity195 and 661 (31%) developed mild @entity73 . A @entity73 point occurred between 4 and 5 years before the clinical diagnosis of @entity195 . Differences between @entity3004 and EAs were observed: EAs had a higher starting level of composite cognitive function, and a change point occurred 4.3 years before @entity195 among @entity3004 and 4.7 years among EAs. The slope of @entity73 after the change point among those developing clinical @entity195 was significantly greater among EAs (0.233 units/y) than among @entity3004 (0.171 units/y; p < .001). This difference in slope of @entity73 persisted after diagnosis of @entity195 so that at the conclusion of observation the difference in average cognitive level was reversed. @entity3004 without @entity73 had a lower average baseline of cognition than EAs, but the slopes of @entity73 were similar. CONCLUSIONS: A prominent change to a steeper slope of @entity73 occurs between 4 and 5 years prior to the diagnosis of @entity195 . The slope of @entity73 after the change point is steeper among EAs than @entity3004 .

A Cognitive Turning Point in Development of Clinical Alzheimer's Disease XXXX and Mild @entity73 : A Biracial Population Study.

@entity1 :: ('9606', 'Species') :: ['participants'] @entity303 :: ('MESH:D003704', 'Disease') :: ['dementia'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive impairment', 'cognitive change', 'cognitive decline'] @entity195 :: ('MESH:D000544', 'Disease') :: ['AD', 'AD dementia', "Alzheimer's disease"] @entity3004 :: ('MESH:C537904', 'Disease') :: ['AAs', 'African Americans']
@entity303 :: (MESH:D003704,Disease) :: ['Dementia']
