Dementia is becoming increasingly common in underdeveloped societies. Methods for detecting, diagnosing, and treating dementia appropriate for application in developing economies is critically important to avoid the emergence of health disparities in care of dementia patients. The Dementia and Disability in Thai Elderly Project (DDP) unites the expertise of the UCLA Alzheimer's Disease Center and the Neurodegenerative Disease and Behavioral Neurology Section of the Division of Neurology of Mahidol University to respond to a newly instituted public health mandate (the Rehabilitation and Disabled Persons Act, BE2534) requiring that each university or medical center take responsibility for the care of patients in their assigned catchment areas in Bangkok. This research will be done primarily in Thailand at Mahidol University in collaboration with Vorapun Senanarong, M.D. as an extension of NIH grant #P50 AG16570. The methodology proposed in the DDP has been accepted by the individual responsible for the Mahidol catchment area, Professor Udom Kachitorn, as the means of detecting and characterizing dementia and disability in Thai elderly. Two thousand-six hundred fifty Thai elderly live in the catchment area and will be screened over a 6-month period in temples, schools, and elderly clubs. We anticipate the identification of 130 individuals with dementia and 450 individuals with cognitive impairment with no dementia (CIND). These patients will be assessed to determine the cause of the dementia and cognitive impairment. These patients plus 100 non-demented, non-disabled controls will be reassessed 1 year later. We hypothesize that the Thai Activities of Daily Living scale will detect disability in 40% of Thai elderly; dementia will be present in 5% of Thai elderly; Alzheimer's disease will account for 60% of the dementia detected in Thai elderly; CIND will be present in 17% of Thai elderly, the 1-year incidence of dementia will be present in those with CIND at baseline; patients with dementia at baseline will exhibit a cognitive decline of 4 Thai Mental Status Examination points per year; and disability will be highly correlated with cognitive deterioration. The phases of the study (training, screening, assessment, and follow-up) will be completed over a 3-year period. Our program is ambitious and substantial cost sharing will be undertaken by Mahidol University. The outcomes of this study are critically important for public health planning of the needs of disabled and cognitively impaired urban Thai elderly. The DDP will serve as a model for the implementation for disability and dementia screening in other catchment areas of Bangkok. The major foreign collaborators and the principal investigator of the UCLA Alzheimer's Disease Center have successfully collaborated on several past projects and have published several manuscripts together.