WHAT LONELINESS LOOKS LIKE IN THE BRAIN

Researchers have found several differences in the brains of lonely people, which will help us to better appreciate the toll of loneliness in today’s society.

Loneliness is increasingly being recognised as a major health problem, and previous studies have shown older people who experience loneliness have a higher risk of cognitive decline and dementia. To help understand how loneliness manifests itself in the brain, a team of scientists from McGill University examined MRI data, genetics and psychological selfassessments of approximately 40,000 middle-aged and older adults. The researchers found several differences in the brains of lonely people. These differences involved regions of the brain involved in inner thoughts such as reminiscing, future planning, imagining and thinking about others. Researchers found that people who felt lonely had a greater grey matter volume in this region. Loneliness also correlated with differences in the fornix: a bundle of nerve fibres that carry signals from the hippocampus to this region. In lonely people, the structure of this fibre tract was better preserved. The fact the structure and function of this region is positively associated with loneliness may be because lonely people are more likely to use imagination, memories of the past or hopes for the future to overcome their social isolation. “In the absence of desired social experiences, lonely individuals may be biased towards internally directed thoughts such as reminiscing or imagining social experiences,” says Nathan Spreng of the Montreal Neurological InstituteHospital (NEURO) at McGill University, and the study’s lead author. Danilo Bzdok, a researcher at NEURO and the Quebec Artificial Intelligence Institute, and the study’s senior author, says we are just beginning to understand the effect of loneliness on the brain. “Expanding our knowledge in this area will help us to better appreciate the urgency of reducing loneliness in today’s society,” he says.