Loneliness and the Brain

Nature news has this interesting piece on the impact of loneliness on human health.  A sample from the article:

The COVID-19 pandemic might ["editorial snark:  ya think!"] have exacerbated loneliness by forcing people to isolate for months or years, although “that data is still emerging”, Kotwal says. Older adults have long been thought of as the demographic most heavily affected by loneliness, and indeed it is a major problem faced by many of the older people that Kotwal works with. But the Cigna Group’s data suggest that loneliness is actually highest in young adults — 79% of those between the ages of 18 and 24 reported feeling lonely, compared with 41% of people aged 66 and older.

Historically, staying close to others was probably a good survival strategy for humans. That’s why scientists think that temporary loneliness evolved — to motivate people to seek company, just as hunger and thirst evolved to motivate people to seek food and water.

In fact, the similarities between hunger and loneliness go right down to the physiological level. In a 2020 study, researchers deprived people of either food or social connections for ten hours. They then used brain imaging to identify areas that were activated by images of either food — such as a heaping plate of pasta — or social interactions, such as friends laughing together. Some of the activated regions were unique to images either of food or of people socializing, but a region in the midbrain known as the substantia nigra lit up when hungry people saw pictures of food and when people who felt lonely saw pictures of social interactions6. That’s “a key region for motivation — it’s known to be active whenever we want something”, says Tomova, who is an author on the study.

Cheers 

Colin