How is dementia diagnosed?

Confirming the diagnosis of dementia can be difficult due to the many diseases and conditions that cause it as well as because its symptoms are common to many other illnesses. However, doctors are able to make the diagnosis based on the results of personal medical history, review of current symptoms, neurological (brain) and cognitive (thinking) tests, laboratory tests, imaging tests (CT, MRI, PET scans) and by interacting with the patient.

Current general symptoms that would indicate dementia are, by definition, a decline in such mental functions as memory, thinking, reasoning, personality, mood or behavior that are severe enough to interfere with the ability to accomplish everyday tasks. Patients undergo mental function testing (memory tests, language skills, reasoning and judgment evaluations, problem-solving tasks, other thinking skill tests) to identify problems in these areas. Interviews with family members and/or close friends who may have noticed changes in these areas are helpful as well.

Laboratory tests rule out other diseases and conditions as the cause of dementia, such as thyroid problems and vitamin B12 deficiency. Similarly, brain scans can look for signs of a stroke or tumor that may be the source of the dementia. A PET scan can determine if amyloid proteins are present in the brain, a marker for Alzheimer’s disease.

Oftentimes, neurologists and geriatricians assist in making the diagnosis.

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