Breakthrough in Alzheimer's Diagnosis: Blood Test Outperforms Traditional Methods

A research team has achieved significant progress towards the long-awaited diagnosis of Alzheimer's disease through a simple blood test. On Sunday, the scientists announced that the blood test was markedly more accurate than the interpretation of cognitive tests and CT scans performed by doctors to signal the disease. The study, published in the journal JAMA, found that the blood test correctly identified whether patients with memory problems had Alzheimer's in about 90% of cases. In contrast, dementia specialists using standardized methods without expensive PET scans or invasive spinal taps achieved an accuracy of 73%, while general practitioners using these methods reached an accuracy of only 61%. These findings were presented on Sunday at the International Conference of the Alzheimer's Association in Philadelphia, marking an important milestone in the quest for affordable and accessible diagnostic tools for Alzheimer’s. This disease affects nearly 7 million Americans and more than 32 million people worldwide. Medical experts believe the results bring the field closer to a day when routine blood tests to check for cognitive impairments could be part of primary medical examinations, similar to cholesterol tests. In recent years, various blood tests for Alzheimer's have been developed. These are mainly used to select study participants and by some specialists to determine whether dementia is caused by Alzheimer's or another factor. The new study was conducted in Sweden, and experts pointed out that for application in the United States, the results should be confirmed in a diverse American population. Experts emphasized that blood tests should only be a step in the screening process and should primarily be used for individuals with memory loss and other symptoms of cognitive impairment—not for cognitively healthy individuals to predict whether they will develop Alzheimer's. Testing recommendations could change if scientists find medications that can delay or halt the pathology of Alzheimer's in individuals who have not yet developed cognitive problems. Medical professionals also underscored that blood tests should only follow evaluations that assess memory and thinking abilities, as well as CT scans to look for alternative causes such as strokes or brain tumors. The results of the blood tests should be confirmed by one of the gold standard methods like PET scans or spinal taps to measure amyloid protein, which accumulates in the brains of Alzheimer's patients and forms plaques.