Two decades of research in Alzheimer disease: looking back to the first volume of ADAD.

During the first two decades of the life of this Journal (ADAD) much progress has been made in our understanding of Alzheimer disease (AD). Advancing knowledge, however, has been accompanied by increasing appreciation of the complexity and heterogeneity of this disease. Prevention and cure continue to elude us as the number of afflicted and the cost of their care continues to increase. New techniques together with long-term prospective follow-up studies, as well as utilization of data accumulated in existing data bases, are needed to move the field forward. We expect that during the next two decades, as new information accrues, reports published in ADAD will continue to contribute to the dissemination and elucidation of critical issues in Alzheimer research.