My fellow Americans, I have recently been told that I am one of the millions of Americans who will be afflicted with Alzheimer’s disease… Unfortunately, as Alzheimer’s disease progresses, the family often bears a heavy burden… I now begin the journey that will lead me into the sunset of my life.”
On November 5, 1994, former US president Ronald Reagan wrote these words in a public letter announcing his diagnosis of Alzheimer’s disease. He died a decade later. More than three decades on, despite major advances in medicine, Alzheimer’s disease remains one of the most feared and least understood illnesses worldwide.
Once viewed largely as a western concern, Alzheimer’s disease is now a growing crisis in countries like India. An estimated 8.8 million Indians over the age of 60 are living with dementia, with Alzheimer’s accounting for nearly 60-70 per cent of cases. As life expectancy increases, this number is expected to nearly double by 2050. Yet, nearly 90 per cent of cases in India remain undiagnosed—often dismissed as “normal ageing” or hidden due to stigma and limited access to specialist care. The burden extends far beyond those diagnosed. In India, caregiving falls overwhelmingly on families, most often women, who typically lack formal training or institutional support. The emotional, physical, and financial toll can be immense. Until recently, confirming Alzheimer’s required PET scans or invasive spinal fluid tests—both largely inaccessible or unaffordable for most Indians. As a result, diagnosis often occurs only after significant cognitive decline, reducing opportunities for early intervention and treatment.That may now be beginning to change.
Researchers at Washington University School of Medicine have developed a promising blood test capable of estimating when someone might begin showing symptoms of Alzheimer’s disease. In a study published in Nature Medicine, the team reported that their model could predict symptom onset within three to four years.
According to Dr Suzanne Schindler, the study’s senior author, blood tests are “substantially cheaper and more accessible than brain scans or spinal fluid tests”. In the near term, such tools could accelerate clinical trials for preventive therapies. Over time, they may help doctors counsel patients and families years before symptoms appear, allowing for earlier planning and intervention. The test works by measuring levels of a protein called p-tau217 in the blood. This biomarker reflects underlying changes in the brain associated with Alzheimer’s, particularly the buildup of amyloid plaques and tau tangles. Importantly, these biological changes can begin years—even decades—before memory loss becomes noticeable.
At present, such blood tests are mainly used to support diagnosis in individuals who already show cognitive symptoms. They are not recommended for cognitively healthy people outside research settings, an important safeguard against unnecessary anxiety or misuse. In May 2025, the US Food and Drug Administration cleared the first blood test for Alzheimer’s disease for individuals over 55 with cognitive impairment. This was followed in October 2025 by clearance of another blood-based test, designed for use in primary care settings to help rule out Alzheimer’s-related pathology. Although currently approved only in the US, these developments signal a significant shift.
Affordable blood tests could transform this landscape. Earlier diagnosis would enable better planning, more efficient use of health care resources, and timely access to emerging treatments or lifestyle interventions. Families would have more time to prepare emotionally and financially. Policymakers, in turn, could begin treating dementia as a public health priority rather than an inevitable part of ageing.
These tests are not a cure. But they represent a critical turning point—from late-stage recognition to early detection and prediction. For a rapidly ageing country like India, this shift offers a measure of hope: for patients, families, and a health care system struggling to keep pace. Alzheimer’s marked the beginning of a difficult journey. Today, science is providing tools to recognise that journey earlier—and to navigate it with greater clarity, preparedness and care.
Shyla Jovitha Abraham, is a health and wellness writer, based in Cleveland, and Dr Jame Abraham, is chairman, department of hematology/medical oncology and professor of medicine at Cleveland Clinic. The views expressed are his own and do not represent the views of Cleveland Clinic.