Social isolation is a growing epidemic. Since the 1980s, the percentage of American adults who say they're lonely has doubled from 20 percent to 40 percent. About one-third of Americans older than 65 now live alone. People in poorer health - especially those with mood disorders like anxiety and depression - are more likely to feel lonely. Social separation is bad for us. Individuals with less social connection have disrupted sleep patterns, altered immune systems, more inflammation and higher levels of stress hormones. One recent study found that ... socially isolated individuals had a 30 percent higher risk of dying in the next seven years, and that this effect was largest in middle age. These effects start early: Socially isolated children have significantly poorer health 20 years later, even after controlling for other factors. The evidence ... is clear. What to do about it is less so. Loneliness is an especially tricky problem because accepting and declaring our loneliness ... can feel as if we're admitting we've failed in life's most fundamental domains: belonging, love, attachment. Dr. John Cacioppo, a psychology professor ... has tested various approaches to treat loneliness. His work has found that the most effective interventions focus on addressing "maladaptive social cognition" - that is, helping people re-examine how they interact with others and perceive social cues. A great paradox of our hyper-connected digital age is that we seem to be drifting apart. However ... human connection lies at the heart of human well-being.