The largest study of its kind has discovered a troubling link between loneliness and dementia. Researchers at Florida State University found that people who experience feelings of loneliness are over 30% more likely to develop dementia than those who don’t.
The research, published in Nature Mental Health, analyzed data from more than 600,000 individuals worldwide, combining results from 21 long-term studies to paint a comprehensive picture of how social isolation affects our cognitive health.
“These results are not surprising, given the mounting evidence that link loneliness to poor health,” says Assistant Professor Martina Luchetti, who led the study, in a university release.
Her team’s work takes on special significance in the aftermath of the COVID-19 pandemic, which forced both the World Health Organization and U.S. Surgeon General to declare loneliness a public health crisis.
The study’s findings suggest that loneliness isn’t just about feeling sad or isolated – it could have serious implications for brain health. The researchers found that feeling dissatisfied with social relationships affects cognitive function regardless of a person’s age or gender. This impact extends beyond general cognitive decline to include specific forms of dementia, including Alzheimer’s disease.
“Dementia is spectrum, with neuropathological changes that start decades before clinical onset,” Luchetti explains. “It is important to continue studying the link of loneliness with different cognitive outcomes or symptoms across this spectrum. Loneliness – the dissatisfaction with social relationships – may impact how you are functioning cognitively, and in daily life.”
The research team conducted a meta-analysis, combining and analyzing data from multiple studies to identify patterns and trends. This approach allowed them to draw conclusions from a massive dataset of over half a million participants, though the researchers note that most data came from wealthy Western nations.
“We know there are rising cases of dementia in low-income countries,” Luchetti says. “Future studies need to gather more data from those countries to evaluate what are the effects of loneliness in different national and cultural contexts.”
The finding of a 31% increase in dementia risk could help shape future strategies for preventing severe cognitive decline.
“Now that there is solid evidence of an association, it is critical to identify the sources of loneliness to both prevent or manage loneliness and support the well-being and cognitive health of aging adults,” Luchetti concludes.