Like an exhibit from a sensational Mafia trial, two decades of research have begun to map out the twisted conspiracy among loneliness, depression, and death.
Take, for instance, the March 2012 edition of Social Science & Medicine. Researchers there published the results of a six-year study of a cross-section of some 2,100 older Americans. They found that, even when other bad health or bad habits (such as smoking) were “factored in,” those who reported the most intense
feelings of loneliness were nearly twice as likely to die as those who didn’t.
“The fact that loneliness continues to predict health outcomes when health behaviors are held constant,” Clemson Assistant Professor Ye Luo wrote for her colleagues, “suggests that loneliness alters physiology at a more fundamental level” than even previously thought.
Earlier research has shown that loneliness contributes to hardened arteries and higher blood pressure, messes with the hypothalamus, cuts back on the body’s ability to fight infections, and even disrupts gene transcription.
Of course, loneliness is a subjective measure. But Luo and many others are convinced that a person’s sense of loneliness has a cascading effect on the other senses, which, in turn, has a cascading effect on a person’s health.
“Our theoretical model of loneliness holds that loneliness activates implicit hyper vigilance for social threat in the environment,” she wrote. “Chronic activation of social threat surveillance diminishes executive functions, and heightened impulsivity influences the tendency of individuals to engage in health behaviors that require self-control.
“Consistent with this notion, among middle- and older-age U.S. adults, loneliness was associated with a lower likelihood of engaging in physical activity and a faster decline in levels of physical activity participation over a two-year follow-up period.”
In other words, the lonelier people feel, the sadder they feel. The sadder they feel, the less likely they are to engage with the world outside.

The Political Economy Of Loneliness

This isn’t just bad news for the individual resident. It’s bad news for the economy.

Earlier this year, researchers in Jerusalem published an analysis on the relationship between elderly depression and elderly reliance on Israel’s national health system. Those older folks who were considered clinically depressed were consistently more likely to seek health care than those who weren’t depressed.

And one of the biggest factors in those people’s depression was … loneliness. A full 70 percent of those patients with clinical depression between 70 and 77 reported feeling lonely, compared with about 28 percent of non-depressed people who felt lonely. In that age group, loneliness was second only to “chronic pain” (about 76 percent) as a factor in depression.

If these findings have any validity, it means that loneliness is a huge drain on the health care system.