The impact of a special care unit (SCU) for Alzheimer's disease (AD) patients will be evaluated. The effects of a specialized program will be separated from the effects of the physical design and separate treatment by a three-group design: (1) The experimental (E) group, a 50-unit specially- designed AD unit in which an individualized multidisciplinary intervention will be conducted; (2) A physically identical unit with similar residents, designated for AD patients, but without the intervention (control unit, C), and (3) a group of 50 AD patients matched for sex, cognitive impairment, and behavioral pathology, housed in 5 other physical units, where a broader mix of AD and nondemented residents exist (scattered control). The contrast between E and (C plus scattered C) will test the full impact of the SCU; the contrast between C and scattered C will test the impact of clustered standard care versus nonclustered standard care. The experimental intervention is based on the Lawton-Nahemow competence-press ecological model and particularly on the aspect of that model that differentiates challenge versus support as routes to optimally adaptive states. The specialized program will attempt to determine resident preference for stimulation versus retreat as a general personality preference and as states that ebb and flow over time. Stimulation in the form of activities engagement, learning of ADL skills, social skills, and personal growth will be matched by interventions allowing retreat, indulgence of privacy, and dependence as therapeutic media. Assessment at baseline, 6-month, and 12-month intervals will assess the outcomes in terms of a number of quality of life (attention, ADL, agitation, meaningful time use, social behavior, affect) and clinical (medical, cognitive, and psychiatric conditions and medication use) criteria.