Covid-19 cases and death reach dangerous levels in Ontario, and many people are concerned about their loved ones, their jobs, resources, and the future. Within this chaos, some people brush off the loneliness and isolation they and others experience in order to focus on immediate concerns. However, long-term loneliness can have a serious impact on a person’s health.
One study by Julianne Holt-Lunstad and her team from Brigham Young University found that loneliness is as harmful as obesity, or smoking 15 cigarettes daily. Another study from Johannes Gutenberg University by Manfred Beutel and colleagues found that lonely people are more susceptible to depression, anxiety disorders, and suicide ideation. This present study, led by R. Nathan Spreng from McGill University, Faculty of Medicine, examined how loneliness manifests in the human brain. Spreng and his team published this study in Nature on December 15, 2020.
The researchers examined genetic data, magnetic resonance imaging (MRI) scans, and data from a questionnaire from 40 000 adults through the UK Biobank, a medical database. The questionnaire asked adults whether or not they often felt lonely. 13.1 per cent of participants answered ‘yes;’ over two-thirds of this group was female. Spreng and team found several differences between the brains of people who were lonely and people who were not lonely.
The brain consists of a network known as the default network. This region is active during passive tasks, such as mind-wandering, imagining, and thinking of others. This present study found that lonely people had a more strongly wired default network than people who were not lonely. Lonely people also had more grey matter in their default networks. Grey matter helps the brain process information, notably from sensory organs.
“In the absence of desired social experiences, lonely individuals may be biased towards internally-directed thoughts such as reminiscing or imagining social experiences. We know these cognitive abilities are mediated by the default network brain regions,” says Spreng.
“So, this heightened focus on self-reflection, and possibly imagined social experiences, would naturally engage the memory-based functions of the default network.”
Spreng and his colleagues also found differences in the fornix. The fornix is a collection of nerves that carry information from the hippocampus to the default network. This was preserved better in lonely people.
“The fornix is the most important major fibre tract or major cable that provides input into the default network,” Danilo Bzdok, the study’s senior author from The Neuro and the Quebec Artificial Intelligence Institute told CTV News. “The thickness of the fornix does indeed predict the vividness of mental imagery of humans. We know that this somehow carries information that is necessary for humans to imagine very detailed and rich pictures in their mind.”
After a year of this pandemic and varying periods of social isolation, this research is relevant to millions of people. It is also unclear about how permanent these effects are; will an increased tendency to self-reflect make it difficult to connect to other people after the pandemic? Or will the brain easily revert back to its default mode of socializing?
“We are just beginning to understand the impact of loneliness on the brain,” says Bzdok. “Expanding our knowledge in this area will help us to better appreciate the urgency of reducing loneliness in today’s society.”