Social Isolation Leads to Lower Brain Volume in Areas Linked with Dementia, Study Finds

Social isolation is common among older adults. A National Academies of Sciences, Engineering, and Medicine report found that it impacts nearly 1 in 4 American adults aged 65 and older. This lack of personal interaction has been linked with an increased risk of many health issues, including dementia. Now, a new study finds that it may also shrink brain volume.

A group of researchers examined nearly half a million older adults in the United Kingdom over more than a decade to determine how isolation impacted their biological and cognitive health. The results, published in the American Academy of Neurology’s journal Neurology, indicate that it can affect brain volume in areas linked with dementia.


Dr. Jianfeng Feng, study author from Fudan University in Shanghai, says, “People who reported high levels of social isolation had significant differences in brain volume, also associated with cognition and dementia. Given the findings of this study, social isolation may be an early indicator of an increased risk of dementia.”

To determine whether participants were isolated, the team asked them three questions: if they lived with others, if they visited with friends and family at least once a month, and if they took part in other social activities like clubs and volunteer work on a weekly basis. If they answered no to at least two of these questions, they were considered to be socially isolated.

In addition to the survey, the researchers conducted medical exams, including MRIs, and had participants take memory tests. The group included 462,619 people, who were an average age of 57 when the study began. They were followed for nearly 12 years.


Among all participants, 9% reported being socially isolated, while 6% felt lonely. Just shy of 5,000 of all participants developed dementia during the course of the study, among whom were 649 of the 41,886 isolated participants, or 1.55% of this group. That was compared with 4,349 of the 420,733 participants who were not isolated, or 1.03%. When adjusting for possible confounding factors, the team found that the isolated adults had a 26% higher risk of dementia than the others.

It didn’t just stop there, though. Participants without those social connections were more apt to have a lower volume of gray matter in areas of the brain linked with learning and thinking.

The team says these findings show the importance of ensuring the older adults in our lives interact regularly with others.


Dr. Feng explains, “Social isolation is a serious yet under-recognized public health problem that is often associated with old age. In the context of the COVID-19 pandemic, social isolation, or the state of being cut off from social networks, has intensified. It’s more important than ever to identify people who are socially isolated and provide resources to help them make connections in their community.”

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