COVID-19 regulations have led to reduced social interaction and periods of isolation, but new research has unveiled the effect this can have on the brain.
Scientists from the Montreal Neurological Institute-Hospital found that the brains of those who reported feelings of loneliness had distinct differences compared to those who did not.
This included different volumes in certain regions, as well as a contrast in how these regions interact with each other.
The 40,000 middle-aged or older patients involved in this study completed a psychological self-assessment to decide whether they were classed as lonely or not.
This data was then compared with their MRI scans from the UK Biobank which allowed them to discover the differences in each patient’s brain.
Most of the differences found revolved around the default network – a region of the brain involved in inner thoughts such as reminiscing, future planning, imagining and thinking about others.
This region was more strongly wired together in lonely people, while their grey matter volume here was also greater.
The study’s authors theorised that this is because lonely people use their area of the brain more due to their isolation. They usually spend more time imagining social situations and reminiscing, leading to increased activity here.
Its lead author Nathan Spreng expanded on this, saying: “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, so this heightened focus on self-reflection, and possibly imagined social experiences, would naturally engage the memory-based functions of the default network.”
Differences were also found in a bundle of nerve fibres called the fornix, which carries signals from the hippocampus to the default network.
Previous studies have shown that loneliness can lead to both mental and physical health problems, with increased focus now being put on the link between this and dementia.
Prolonged periods of isolation, as well as social distancing measures due to COVID-19 has the potential to dramatically increase the number of people feeling the effects of loneliness.
Understanding the link between this and cognitive decline could be key when it comes to reducing the onset of neurological conditions.
“We are just beginning to understand the impact 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,” says Danilo Bzdok, the study’s senior author.
The researchers now say they will use this data to try and gain a better understanding of the progress of dementia, in-particular looking at Alzheimer’s disease.
