Currently, there are no dementia-specific blood tests available to the public, but ongoing research may introduce such tests in the near future.
As the world’s population gets older, the prevalence of Alzheimer’s disease and other forms of dementia is on the rise, highlighting the growing need for efficient and accurate diagnostic tools.
Currently, doctors use cognitive evaluations, tests, and brain scans to diagnose dementia. However, recent advancements in medicine are paving the way for a revolutionary shift: the detection of Alzheimer’s through blood tests.
A blood test for diagnosing dementia would be a game-changer. It could potentially offer a more reliable, noninvasive, and more accessible method compared to current complex procedures that cannot rule in or rule out dementia, such as brain imaging and cerebrospinal fluid analysis.
However, researchers are actively working on blood tests that target specific biomarkers associated with Alzheimer’s disease.
These biomarkers include substances such as:
- amyloid β-peptide (Aβ) oligomers
- phosphorylated tau
- neurofilament light (NfL)
- glial fibrillary acidic protein (GFAP)
These blood tests could be available in the near future and will likely play a critical role in diagnosing Alzheimer’s disease.
Currently, there’s no single definitive blood test that can diagnose dementia or Alzheimer’s disease. However, healthcare professionals may order a variety of blood tests to help assess your cognitive function, rule out other potential causes of symptoms, and evaluate overall health.
These tests may include:
- Complete blood count (CBC): A CBC provides information about the numbers and types of blood cells. While it doesn’t directly diagnose dementia, it can help identify underlying conditions that might contribute to cognitive symptoms.
- Basic metabolic panel (BMP) or comprehensive metabolic panel (CMP): These panels measure electrolytes, glucose, and other chemicals in the blood to assess kidney and liver function, blood sugar levels, and more. Abnormal results might indicate conditions affecting cognition.
- Thyroid function tests: Tests such as thyroid-stimulating hormone (TSH) and thyroxine (T4) help evaluate thyroid function. Thyroid imbalances can sometimes mimic dementia symptoms.
- Vitamin B12 test: Vitamin B12 deficiency can lead to neurological symptoms that resemble dementia. Testing B12 levels can help identify deficiencies.
- C-reactive protein (CRP) and sedimentation rate (ESR): These tests can detect inflammation in the body, which might be associated with certain types of inflammatory diseases.
- Lipid profile: This profile evaluates cholesterol levels, which are linked to cardiovascular health. Cardiovascular issues can contribute to cognitive decline.
- Tests for infections: Depending on your symptoms, doctors might order tests to rule out infections that can affect the brain, like HIV or syphilis.
To definitively diagnose dementia and its specific type, more comprehensive assessments, such as cognitive testing and medical history review, are often needed.
Currently, the best way to detect dementia involves a combination of clinical assessments, cognitive tests, and medical history reviews. Brain imaging may also be used to aid diagnosis.
In the future, blood tests could offer easier and more accessible ways to diagnose dementia, without the need for complex procedures.
The following blood tests are currently in development or are still undergoing testing:
- Simoa (single molecule array) technology:
Researchersused a new blood test called Simoa to measure a protein called ptau181 in the blood plasma of more than 400 people. They found that the ptau181 levels in those with Alzheimer’s were different from those in non-affected individuals. The test could also differentiate Alzheimer’s from another brain disorder called frontotemporal lobar degeneration.
- Blood tests for ptau217 and ptau181: Researchers explored ptau217, a tau protein variant, as a potential early marker for Alzheimer’s. One
studyshowed that ptau217 in the blood can distinguish individuals with Alzheimer’s-related brain changes. Another study used mass spectrometry to measure ptau217 in blood, accurately identifying Alzheimer’s brain damage.
- SOBA (soluble oligomer binding assay): Toxic amyloid beta (Aβ) oligomers contribute to Alzheimer’s disease.
Researcherscreated a test called SOBA to find these harmful oligomers in blood and cerebrospinal fluid. SOBA accurately detected Alzheimer’s and related disorders and could potentially help diagnose other conditions like Parkinson’s disease.
- Finger prick blood test (ongoing development): This ongoing research aims to develop a blood test using a finger prick to measure Alzheimer’s-related biomarkers such as neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and phosphorylated tau (ptau181 and ptau217).
Currently, dementia-specific blood tests are mostly in the research and development stage and aren’t widely available for routine clinical use. These tests are being studied in various research settings and clinical trials.
If you’re seeking diagnostic tests like a complete blood count (CBC) to rule out other potential causes of cognitive symptoms, you would typically visit a primary care physician or a family doctor. These doctors are often the first point of contact for general health concerns and can help determine whether further evaluation is needed.
In cases of cognitive impairment, memory loss, or suspected dementia, you might be referred to a neurologist, geriatrician, or a specialist in memory disorders. These specialists can conduct more comprehensive evaluations, order specific tests and assessments (such as cognitive tests, brain imaging, or blood tests), and provide a definitive diagnosis.
While dementia-specific blood tests are still in the research and development stage, promising advancements are being made. It’s anticipated that these tests could become available in the near future, offering a quicker and less invasive way to diagnose dementia.
Until then, dementia will continue to be detected through comprehensive clinical evaluations, cognitive tests, brain imaging, and medical history.