An individualized approach to tracking and treating Alzheimer's disease.

There can be substantial variation in the expression of Alzheimer's disease. Patients vary in who is affected (e.g., education, age at onset), in how they are affected (e.g., neuropathological profile, comorbidities), and in when they present (i.e., stage of illness). Even people with similar starting profiles can have dramatically different courses. For these reasons, tracking disease progression in individuals and the effects of treatment on them can be challenging. This variability further complicates the difficulty of dementia's high dimensionality--Alzheimer's disease affects many aspects of cognition, function, and behavior.