In a significant development, a new blood test for Alzheimer’s has been able to detect the illness as accurately as other more expensive and invasive methods, The New York Times reported on Tuesday, 28 July.

The promising test could determine whether people with dementia had Alzheimer’s instead of another condition, and could identify signs of the disease almost 20 years before memory and thinking problems are expected to show up in the patients.

Scientists believe that blood tests such as this would help speed up the search for new therapies by making it ‘faster and cheaper to screen participants for clinical trials’.

Dr Rosa Sancho, head of research at Alzheimer's Research UK, was quoted in the BBC as explaining that the previous clinical trials of drugs had failed because the patients enrolled in them were too far advanced in their illness, and by that time it was "too late".

Since the test diagnoses the illness in its early stages and before symptoms appear, it could help with trying new treatments for a disease that has no cure so far.

This newly developed test measures a form of the tau protein found in the brain in Alzheimer’s and showed better results than MRI brain scans; was equally good as PET scans or spinal taps and was ‘nearly as accurate’ as autopsies - which is the most accurate diagnostic method. Researchers found that measuring this protein, p-tau217, could predict Alzheimer's dementia with 96% accuracy, BBC reported.

The research has been published in JAMA and was presented at the Alzheimer’s Association International Conference.