Social isolation in elderly poses dementia risk: Study

Bengaluru: Social isolation might influence cognitive performance and impact brain volume in the elderly, putting them at risk for developing dementia, according to findings from an ongoing study of Indian patients.

The study by the Centre for Brain Research (CBR), Indian Institute of Science (IISc), spotlights the issue of social isolation, which researchers said is qualitatively different from loneliness, and how tackling the problem could help in reducing the prevalence of dementia.  

The findings emerged from CBR’s Tata Longitudinal Study on Aging (TLSA) in Bengaluru — also called the CBR-TLSA — where cognitively healthy people aged 45 and above were  evaluated to understand risk and protective factors associated with dementia.

The paper, which has been accessed by DH, will be published in the Asian Journal of Psychiatry's volume 102 coming out in December. 

“While loneliness and social isolation are inter-related, loneliness is probably a subjective feeling. A person can be surrounded by people and still feel lonely. But social isolation is a more of an objective phenomenon," Dr Abhishek Menesgere, the author of the paper, told DH.

Social isolation can be measured by the number of friends, colleagues, family members and relatives one has and what roles they play, including being a parent, spouse, sibling, colleague, grandparent and volunteer. How often a person gets to interact with their network and perform different roles and activities indicate whether the person is socially isolated or not.

“For example, if he/she has friends, how many friends does he/she have? Does he/she meet them regularly, at least once every two weeks? These responses give us one specific score,” Dr Menesgere said. The more a person plays an active role in his/her life and interacts with people, the higher the scores will be.

The analysis indicated that participants with lower network diversity scores had statistically significant lower scores in cognitive assessments. The isolation affects one’s brain on a molecular level: these participants also had lower brain volume, with their hippocampus, which is the part of the brain responsible for learning and memory, also being affected, as indicated by MRI scans.

“Even if you are not fully isolated, if you are not engaging in all the roles you are supposed to be engaging in, you are likely to be at risk of developing dementia,” he added. 

Dr Thomas Gregor Isaac, associate professor at CBR, cited the Lancet Commission report and said if social isolation is eliminated or controlled in the elderly, 5 per cent of the prevalence of dementia can be reduced.

For the study, a cross-sectional analysis of data from 1,484 participants — 757 men and 727 women — with a mean age of 62.6 years was conducted to understand cognitive performance.

These participants completed baseline assessments between June 2015 and December 2023. They underwent a series of cognitive evaluations and detailed assessments, besides brain scans and biochemical tests.

The social network index was used to assess participants’ social isolation scores. People with major neurological illnesses, severe visual impairments and hearing impairment were excluded from the assessments.

Reforms needed

India's population is ageing quickly and family dynamics are rapidly shifting, which means that the burden of dementia in India will rise if ageing people are left with fewer roles to play in society.

The CBR study suggests the need for public policy reforms to improve the social conditions of the elderly and reduce dementia prevalence in India, which is projected to touch 1.68 crore by 2036.