Alzheimer’s disease and other dementias

Dementia is defined as a syndrome consisting of progressive impairment in memory and other cognitive deficits (aphasia, apraxia, agnosia, or disturbance in executive function) in the absence of another explanatory central nervous system disorder, depression, or delirium, sufficient to interfere with activities of daily living. In recent years there has been a move to consider and classify patients with less severe forms of cognitive impairment—so-called mild cognitive impairment—and non-memory presentations, with the latest DSM-V criteria identifying individuals with major or minor neurocognitive syndromes. Ongoing research using biomarkers suggest that there is a long presymptomatic phase for many causes of dementia.