Researchers connect loneliness with heightened risk of dementia in largest study of its kind

New research led by Florida State University College of Medicine faculty quantified the association between loneliness and dementia by analysing data from more than 600,000 people around the world — the largest study of its kind.

The meta-analysis of 21 longitudinal studies showed that experiencing feelings of loneliness increased the risk of developing dementia by 31 per cent.

The research was published in Nature Mental Health.

Assistant Professor Martina Luchetti, who led the study, said: “These results are not surprising, given the mounting evidence that link loneliness to poor health.

“Dementia is spectrum, with neuropathological changes that start decades before clinical onset.

“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 analysis revealed that loneliness is a major risk factor for cognitive impairment, independent of age or sex.

It also linked loneliness to specific causes of dementia, such as Alzheimer’s disease, and cognitive impairments that can occur before a diagnosis.

The team’s work was spurred by the World Health Organization and U.S. Surgeon General, who declared loneliness a public health crisis in the wake of the COVID-19 pandemic and its associated social restrictions.

Luchetti said: “There has been a lot of interest in the consequences of loneliness for health.

“It is important to understand why and under what circumstances it increases risk for late life dementia.”

Although data for the study included subjects from around the world, most of it was collected from people in wealthier Western Hemisphere cultures.

Future research should incorporate more data from other countries, Luchetti said.

The researcher added: “We know there are rising cases of dementia in low-income countries.

“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 meta-analysis results provide information that can guide future prevention and intervention efforts.

Luchetti said: “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.”