Loneliness has been shown to predict the progression of Alzheimer's disease. And middle-aged people who are lonely tend to be less motivated to eat well, exercise and get enough sleep. They have lower self-esteem, which results in self-destructive behavior like excessive drinking.
Once loneliness becomes chronic, getting better can't be achieved just by "coming out of one's shell," the authors say. What is required is a holistic approach.
Human beings are inherently social creatures. We care what others think of us. Social interaction and affirmation are basic necessities.
That's why in history, banishment has been the most severe punishment short of torture and death. It's also why teenagers use ostracism, the deliberate infliction of emotional pain for selfish ends - often with tragic consequences.
Although loneliness may put one at greater risk of depression, the authors say, "loneliness and depression are in many ways opposites." Unlike depression, loneliness "is not a mental disorder â?¦."
"Loneliness, like hunger, is a warning to do something to alter an uncomfortable and possibly dangerous condition. Depression makes us apathetic. Whereas loneliness moves us forward, depression holds us back," they explain.
A persistent sense of rejection, however, can impair one's cognition and lead to the kind of self-defeating behaviors (being critical or defensive, or aloof, for example) that result in rejection and isolation, thus perpetuating the cycle.
Although loneliness is not an illness and therefore cannot be treated with drugs, Cacioppo and Patrick say, cognitive behavioral therapy can help by changing how people choose to see and react to things.
"By reframing our cognitive perceptions, we can begin to change our lives," they write.
Part of their program goes by the acronym EASE.
E is for "Extend yourself." Take small steps toward interacting with others.
A is for having an "Action plan." Join a club or volunteer at something, for example.
S is for "Selection." Pursue those friendships that seem most promising.
E is for "Expect the best." Be positive.
For these two biologists, their book isn't just a way of explaining their research, but is intended to help people.
"It is my belief that, with a little encouragement, most anyone can emerge from the prison of distorted social cognition and learn to modify self-defeating interactions," Cacioppo writes. "What feels like solitary confinement, in other words, need not be a life sentence."