Dementia Diagnosis

Dementia was diagnosed according to standardized criteria at the time of study from the Diagnostic and Statistical Manual, Fourth Edition, and required impairment in memory plus at least 1 additional cognitive domain, accompanied by evidence of decline from a previous level of functioning.³¹ A licensed neuropsychologist used normative data to determine whether impairment existed in any of the 5 cognitive domains.³² A physician independently interviewed and examined each participant, completed a Clinical Dementia Rating scale, and documented a clinical impression of whether dementia was present.^33–35 Final diagnostic determination was made at consensus case conferences attended by the neuropsychologist and a board-certified neurologist. Diagnosis of AD was made in individuals with dementia who met clinical criteria for probable or possible disease established by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer Disease and Related Disorders Association.³²