Six institutions have joined in the creation of the Massachusetts Alzheimer's Disease Research Center (ADRC): four Harvard- affiliated hospitals (Massachusetts General, Brigham and Women's, Beth Israel, and McLean Hospitals); the University of Massachusetts Medical Center; and Massachusetts Institute of Technology. This regional consortium unites a large group of researchers and clinicians with established and potential interests in Alzheimer's disease (AD); it capitalizes on formalized interactions and focuses efforts on improving the diagnosis, understanding the basic mechanisms, and developing treatments for AD. By creating a research capacity and collective intelligence that exceeds the sum of its parts, the Center stimulates investigations b the exchange of ideas, techniques, and experience. A Clinical Core comprising units at MGH, BIH, and UMMC has been established to enroll, diagnose, and follow patients with dementia, provide a pool of patients for clinical investigation, and to collect systematic clinical data regarding the features of AD. A Data Management Core has been established to store information on all patients in the clinical units and all postmortem examinations; personnel in this Core also assist in protocol design and statistical analyses. A Neuropathology Core establishes diagnoses on all brains obtained, and operates a brain bank, storing tissue of AD patients suitable for chemical, histologic, histochemical, and immunocytochemical studies. Research projects examine major issues in AD: new diagnostic methods; reliable information on clinical course; genetic and biochemical aspects of its etiology; the identity and quantity of neural elements affected; and the biologic basis of clinical manifestations. Through the Harvard Geriatric Educational Center, professional training and continuing medical education programs have been expanded. Quarterly workshops on topics of fundamental neurobiological importance are planned with visiting scientists to exchange ideas with ADRC members.