Digital biomarkers for dementia are emerging as a powerful new tool in neuroscience, offering hope for early detection of one of the world’s fastest-growing neurological disorders. In a recent interaction, Prof. K.V.S. Hari, Director of the Centre for Brain Research (CBR) at the Indian Institute of Science (IISc), Bengaluru, explained how technology-driven biomarkers could transform dementia research, diagnosis, and prevention—especially in India, where the ageing population is rising rapidly.
This article explores the science, significance, challenges, and future potential of digital biomarkers for dementia, while highlighting India’s unique role in shaping global brain-health research.
Understanding Dementia: A Growing Global and Indian Crisis
Dementia is not a single disease but an umbrella term covering multiple neurological conditions that affect memory, thinking, language, and daily functioning. Alzheimer’s disease is the most common form, followed by vascular dementia and other neurodegenerative disorders.
Why Dementia Is a Silent Epidemic
- Dementia develops slowly and silently, often over 15–20 years
- Symptoms appear only after significant brain damage has already occurred
- Many people mistake early signs for normal ageing
- By the time diagnosis happens, treatment options are limited
Globally, over 55 million people live with dementia, and this number is expected to triple by 2050. India, with its rapidly ageing population, is projected to face one of the largest dementia burdens in the world.
India’s Ageing Population and Dementia Risk
India is undergoing a major demographic shift. Improved healthcare and life expectancy mean more people are living longer—but longevity also increases the risk of age-related brain disorders.
Key Indian Context
- India may have over 340 million elderly people by 2030
- Dementia prevalence is estimated at 7–8% among older adults
- Awareness remains low, especially in rural areas
- Diagnosis often happens very late—or not at all
This makes early detection not just a medical priority, but a public health necessity.
Why Traditional Dementia Detection Falls Short
Traditional dementia diagnosis relies on:
- Clinical interviews
- Memory and cognitive tests
- Brain imaging (MRI, PET scans)
- Blood or cerebrospinal fluid biomarkers
While effective, these methods have limitations:
Limitations of Conventional Methods
- Expensive and inaccessible for large populations
- Hospital-based, not suitable for long-term monitoring
- Often detect dementia after symptoms appear
- Not scalable for a country like India
This is where digital biomarkers for dementia come into play.
What Are Digital Biomarkers for Dementia?
Digital biomarkers are objective, measurable indicators of health collected using digital devices such as smartphones, wearables, sensors, and AI-powered software.
Unlike traditional biomarkers, digital biomarkers:
- Can be collected continuously
- Capture real-world behaviour
- Detect subtle changes long before symptoms appear
Examples of Digital Biomarkers
- Speech and language patterns
- Gait and walking speed
- Hand movement and motor coordination
- Eye movement and reaction time
- Sleep patterns
- Cognitive task performance on apps
Prof. K.V.S. Hari explains that these signals can reveal early brain changes years before dementia is clinically diagnosed.
The Science Behind Digital Biomarkers
The brain controls everything we do—from speech and movement to decision-making and emotions. Even minor brain changes affect these functions in subtle ways.
How Digital Biomarkers Work
- Data Collection
Sensors, smartphones, or wearable devices collect behavioural data - Signal Processing
Raw data is cleaned and structured - AI and Machine Learning
Algorithms identify patterns linked to cognitive decline - Longitudinal Tracking
Changes are monitored over years, not just one-time tests
This approach allows researchers to identify preclinical dementia, a stage where intervention may still be effective.
Centre for Brain Research (CBR), IISc: Leading the Mission
The Centre for Brain Research at IISc Bengaluru is at the forefront of dementia research in India. Under Prof. Hari’s leadership, the centre focuses on understanding brain ageing across India’s diverse population.
Why CBR Is Unique
- Focus on healthy individuals, not just patients
- Long-term population-based studies
- Integration of neuroscience, engineering, AI, and medicine
- India-specific data instead of Western models
CBR’s goal is to predict, prevent, and delay dementia, not just diagnose it.
Urban and Rural Cohort Studies: A Landmark Initiative
One of CBR’s most important contributions is its large-scale longitudinal cohort studies.
Urban Cohort (Bengaluru)
- Started in 2015
- Around 1,000 participants
- Annual cognitive, clinical, and lifestyle assessments
Rural Cohort (Kolar District, Karnataka)
- Started in 2018
- Around 10,000 participants
- Follow-up every two years
These studies allow researchers to observe how:
- Lifestyle
- Education
- Diet
- Physical activity
- Environment
affect brain ageing and dementia risk.
Why Digital Biomarkers Are Ideal for Long-Term Studies
Traditional tests once every few years can miss important changes. Digital biomarkers solve this problem.
Advantages
- Continuous monitoring
- Low-cost data collection
- Scalable to millions of people
- Suitable for rural and remote areas
- Less invasive
For example, changes in how a person walks or speaks into a smartphone over time may indicate early cognitive decline.
Role of Artificial Intelligence and Data Science
Digital biomarkers generate massive amounts of data. Making sense of this data requires advanced AI and machine learning techniques.
AI in Dementia Research
- Pattern recognition in speech and movement
- Predictive models for cognitive decline
- Risk stratification of individuals
- Personalized intervention strategies
CBR integrates engineers, neuroscientists, clinicians, and data scientists to build robust AI-driven models for brain health.
Why India Needs Its Own Dementia Models
Most global dementia research is based on Western populations. This is problematic for India.
Key Differences
- Genetics
- Nutrition and diet
- Education levels
- Multilingual speech patterns
- Environmental exposure
Digital biomarkers trained on Western data may not work accurately in India. CBR’s India-centric research ensures relevance and reliability.
Digital Biomarkers and Early Intervention
Early detection opens the door to preventive strategies, even when there is no definitive cure.
Potential Interventions
- Lifestyle changes (exercise, diet, sleep)
- Cognitive training
- Management of diabetes, hypertension, and depression
- Delaying disease progression
Research suggests that even delaying dementia onset by 5 years could reduce disease burden by nearly 50%.
Ethical, Privacy, and Data Challenges
While promising, digital biomarkers raise important concerns.
Key Challenges
- Data privacy and consent
- Secure storage of sensitive health data
- Avoiding misuse of AI predictions
- Ensuring accessibility and inclusivity
CBR emphasizes ethical research frameworks and participant consent, especially when dealing with long-term digital monitoring.
Global Collaborations Strengthening Indian Research
CBR collaborates with international institutions such as the UK Dementia Research Institute (UK DRI).
Benefits of Collaboration
- Shared expertise
- Cross-cultural validation of biomarkers
- Global impact of Indian data
- Training and fellowships
These partnerships position India as a global leader in dementia research, not just a data consumer.
Future of Digital Biomarkers in Healthcare
Digital biomarkers could soon become part of routine healthcare.
What the Future May Look Like
- Smartphone apps for brain health screening
- Wearables that monitor cognitive risk
- AI alerts for doctors and caregivers
- Integration with national health programs
For a country like India, this could mean early detection at scale, even in underserved regions.
Policy Implications and Public Health Impact
Prof. Hari stresses the need for dementia to be recognized as a major public health issue.
Policy Opportunities
- National dementia registry
- Brain health screening programs
- Funding for digital health research
- Training healthcare workers
Digital biomarkers could help governments plan better, allocate resources efficiently, and reduce long-term healthcare costs.
Why This Research Matters Now More Than Ever
India stands at a crossroads:
- A rapidly ageing population
- Rising chronic disease burden
- Expanding digital infrastructure
Digital biomarkers for dementia bring together technology, neuroscience, and public health at the perfect moment.
Conclusion: A New Era in Dementia Detection
Digital biomarkers for dementia represent a paradigm shift—from late diagnosis to early prediction and prevention. Through pioneering work at IISc’s Centre for Brain Research, India is building a future where dementia can be detected years before symptoms appear.
By combining long-term population studies, AI-driven analysis, and India-specific data, researchers like Prof. K.V.S. Hari are redefining how we understand brain ageing. The impact of this work could extend far beyond India, influencing global dementia research and care.
As technology advances and awareness grows, digital biomarkers may soon become one of the most powerful tools in protecting brain health—offering hope to millions before dementia takes hold.
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