In this proposal, we will focus on developing and testing a valid cognitive screening instrument suitable both for use in Ballabgarh and for comparisons with the Mon Valley data. Pilot data is provided showing the feasibility of this enterprise. We will systematically identify, translate, and modify appropriate test items, pretest them on volunteers, assemble them into tests of various cognitive domains, and compile a cognitive screening battery as analogous as possible to that used in the Mon Valley studies. We will then pilot-test the battery on a community sample, examine the distribution of scores in the population, and make further modifications to the instrument. After establishing reliability and validity, we will field-test the cognitive screen on a 10% community sample of the elderly (approximately 430 subjects aged 55 and older) in Ballabgarh, concurrently measuring functional ability with a specially developed scale. The entire sample will then be diagnostically evaluated for dementia, using standard criteria. The psychometric properties, sensitivity, and specificity of the screening instrument will be determined, and the data compared with Mon Valley results to identify similarities and differences in the distributions of test scores, age- affects, predictive power, and associations with other variables. The result will be a relatively culture-fair, and optimally sensitive and specific, community screening tool for dementia, which can be used for epidemiological studies in the target population and for comparison with the Mon Valley population; it will also be a first step for a more universally applicable cross-national screening instrument. The development of such an instrument is an essential step towards our long- term goal of conducting a prospective community study to compare the incidence and characteristics of and risk factors for the dementias in the Indian and American populations.