Key TakeawaysA new blood test for Alzheimer’s shows 91% accuracy in diagnosing the condition, potentially improving early diagnosis and access to treatments.Using blood tests alongside cognitive assessments could reduce the time to diagnose Alzheimer’s, helping more patients access early treatments.Current diagnostic tools like spinal taps and PET scans are less accessible, making the blood test a promising alternative for earlier and more accurate detection of Alzheimer’s.

Key Takeaways

A new blood test for Alzheimer’s shows 91% accuracy in diagnosing the condition, potentially improving early diagnosis and access to treatments.Using blood tests alongside cognitive assessments could reduce the time to diagnose Alzheimer’s, helping more patients access early treatments.Current diagnostic tools like spinal taps and PET scans are less accessible, making the blood test a promising alternative for earlier and more accurate detection of Alzheimer’s.

A recentJAMAstudy shows that blood tests could significantly improve the diagnosis of Alzheimer’s. Research shows that a test that determines the likelihood of amyloids, specifically, is 91% accurate at detecting the condition.

Experts say faster diagnosis is critical because there are two effective Alzheimer’s treatments currently on the market—LeqembiandKisunla—as well as others in the pipeline. Both can potentially delay the progression of the disease, but only if patients get the drugs at the earliest stages of Alzheimer’s.

Often, however, patients are not diagnosed until it’s too late to try the medications.

“Blood tests have the potential to increase the accuracy of early diagnoses and maximize the opportunity to access Alzheimer’s treatments as early as possible for better outcomes,” saidMaria C. Carrillo, PhD, Alzheimer’s Association chief science officer and medical affairs lead,in a statement about the study.

How Does the New Blood Test Compare to Current Diagnostic Tools for Alzheimer’s?

Will Doctors Use a New Blood Test for Alzheimer’s?

TheJAMAstudy, which was presented at the Alzheimer’s Association International Conference in July, included over 1,200 patients who saw either a primary care doctor or a dementia specialist. Patients were given in-office cognitive and memory tests, a blood test, and were sent for either a spinal tap or a brain imaging test called a PET scan.

“In-office tests and spinal taps or PET scans are the most common current way to accurately diagnose Alzheimer’s disease, but not everyone is referred to or has access to those tests, which can significantly delay the diagnosis,” Schindler said.

Researchers tested all of the blood samples for a protein called phosphorylated tau, which can develop before cognitive issues start and can predict the likelihood of amyloid plaques in the brain. When they compared the results, they found that the initial diagnosis of primary care doctors was 61% accurate, the dementia specialists were 73% accurate, and the blood test was 91% accurate at diagnosing Alzheimer’s.

Blood Tests Should Speed Up Time to Diagnosis

If blood tests were used to rule out Alzheimer’s, the average wait times would drop to 13 months, researchers say. That’s because the condition could be ruled out sooner, and far fewer patients would need to see a specialist.

“Our results suggest using blood tests to identify potential candidates for treatments could make a significant difference in treating people with early Alzheimer’s,” said lead study authorSoeren Mattke, MD, DSc, director of the Brain Health Observatory at the University of Southern California, Los Angeles,in a statement. “Currently, eligible patients are falling outside of the treatment window because it takes so long to receive a diagnosis.”

What This Means For YouPatients interested in an Alzheimer’s blood test can ask their doctors about it now or ask for a referral to a dementia specialist who may be more likely to know about and even use the tests. It’s unlikely, for now, that the tests will be used alone, and patients should expect a full battery of in-office tests, as well as imaging scans or a spinal tap. While some insurance plans may pay for part of the cost of these blood tests, not all do.

What This Means For You

Patients interested in an Alzheimer’s blood test can ask their doctors about it now or ask for a referral to a dementia specialist who may be more likely to know about and even use the tests. It’s unlikely, for now, that the tests will be used alone, and patients should expect a full battery of in-office tests, as well as imaging scans or a spinal tap. While some insurance plans may pay for part of the cost of these blood tests, not all do.

2 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Palmqvist S, Tideman P, Mattsson-Carlgren N, et al.Blood biomarkers to detect Alzheimer disease in primary care and secondary care.JAMA.Published online July 28, 2024. doi:10.1001/jama.2024.13855Schindler SE, Petersen KK, Saef B, et al.Head-to-head comparison of leading blood tests for Alzheimer’s disease pathology.medRxiv. Preprint posted online July 3, 2024. doi:10.1101/2024.06.12.24308839

2 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Palmqvist S, Tideman P, Mattsson-Carlgren N, et al.Blood biomarkers to detect Alzheimer disease in primary care and secondary care.JAMA.Published online July 28, 2024. doi:10.1001/jama.2024.13855Schindler SE, Petersen KK, Saef B, et al.Head-to-head comparison of leading blood tests for Alzheimer’s disease pathology.medRxiv. Preprint posted online July 3, 2024. doi:10.1101/2024.06.12.24308839

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Palmqvist S, Tideman P, Mattsson-Carlgren N, et al.Blood biomarkers to detect Alzheimer disease in primary care and secondary care.JAMA.Published online July 28, 2024. doi:10.1001/jama.2024.13855Schindler SE, Petersen KK, Saef B, et al.Head-to-head comparison of leading blood tests for Alzheimer’s disease pathology.medRxiv. Preprint posted online July 3, 2024. doi:10.1101/2024.06.12.24308839

Palmqvist S, Tideman P, Mattsson-Carlgren N, et al.Blood biomarkers to detect Alzheimer disease in primary care and secondary care.JAMA.Published online July 28, 2024. doi:10.1001/jama.2024.13855

Schindler SE, Petersen KK, Saef B, et al.Head-to-head comparison of leading blood tests for Alzheimer’s disease pathology.medRxiv. Preprint posted online July 3, 2024. doi:10.1101/2024.06.12.24308839

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