Dementia prevalence higher than national average in Karnataka

Karnataka is among 11 states with dementia prevalence higher than the national average, according to the first nationwide study on such mental illness, which also recorded an all-India burden much above than earlier estimates.

The study by an international team has estimated that about 88 lahk Indians older than 60 years live with dementia, equivalent to a prevalence rate of 7.4% across the country. Karnataka's prevalence rate is marginally higher at 7.61% whereas Jammu and Kashmir top the list with 11.04%.

The new estimate, based on samples of ageing people drawn from 18 states, goes way beyond a previous estimate of 37 lakh people affected by dementia in 2010 with the numbers doubling by 2030. The new study has also found that dementia is more prevalent among females than males and in rural than urban areas.

With India becoming the world’s most populous nation, the country faces a potential health threat with a sharp rise in rise in the number of people suffering from dementia because age is the strongest and best-known risk factor for this common mental health disorder.

But there was no pan-India estimate on the prevalence as previous studies on dementia cover only six of the 36 states and union territories. This is where an international team headed by economist Jinkook Lee from the University of Southern California, Los Angeles had researchers from 15 Indian hospitals chipped in.

"We conducted a nationally representative study of late-life cognition and dementia in India and estimated 7.4% of people aged 60 years and older lived with dementia (8.8 million individuals). Dementia prevalence was higher among females than males and higher in rural than in urban areas,” the team reported.

The researchers recruited more than 71,000 individuals for a long-term study on the well-being and health needs of the ageing population, of which nearly 31,500 were above 60 years of age when they were recruited.

Among the senior citizens, 4,096 persons agreed to be interviewed on dementia following which there had been a clinical consensus to pick up 2,528 elderly persons for the study.

The research found considerable cross-state variations in dementia prevalence, with the lowest prevalence in Delhi at 4.5% and the highest in Jammu and Kashmir at 11.0%. Other states with higher-than-national-average prevalence are Odisha (9.87), West Bengal (9.23), Assam (8.47), Himachal Pradesh (8.43), Kerala (8.27), Telangana (8.27), Uttar Pradesh (7.92), Andhra Pradesh (7.74) and Maharashtra (7.61).

“We found substantial variation across states, and cross-state differences in socio-demographic characteristics drive most of this variation. Different levels of educational attainment across states could contribute to cross-state differences in various dementia risk factors, such as under-nutrition, uncontrolled cardiovascular disease, and exposure to indoor air pollution,” the team reported in Alzheimer’s and Dementia.

If prevalence stays the same, the number of people with dementia is projected to reach nearly 1.7 crore in 2036 due to the growth in the older Indian population.

In 2010, the Alzheimer’s and Related Disorders Society of India estimated that 3.7 million Indians had dementia and projected that this number would double by 2030. “Our findings suggest this might have been an underestimate. The number doubled a decade earlier, reaching 8.8 million in 2019. Therefore, the need to scale up policies to prevent and manage dementia in India is urgent,” the researchers said.

“We also found significant heterogeneity across states. This means that the burden of dementia cases is unevenly distributed across states and requires different levels of local planning and support.”