How is Alzheimer's disease primarily diagnosed?

Alzheimer's disease is primarily diagnosed through a combination of clinical evaluations, cognitive testing, and the exclusion of other potential causes of dementia. However, an autopsy is considered the definitive way to confirm Alzheimer's disease because it allows for the examination of brain tissue for characteristic changes associated with the condition, including amyloid plaques and neurofibrillary tangles.

In live patients, the diagnosis is often based on clinical criteria and assessments rather than a single definitive test, which is why relying on autopsy results is considered confirmation post-mortem. Although patient interviews, brain imaging, and family history play crucial roles in gathering information and ruling out other causes of cognitive decline, they do not provide the definitive diagnosis of Alzheimer's disease in the way an autopsy does.