Good article. Makes lots of sense why I feel lonely all the time even in a crowd (which is rare for me to be in anyway).

Loneliness isn't about being alone, it's about not feeling connected.

The need for connection, and the enforcement power of withdrawing that connection, is evident even among chimpanzees. In chimp society, as in every human culture ever studied, infractions against the social order are punished by some form of ostracism. Well along the path of cultural development, banishment remained the most severe stricture, short of torture or death, imposed by kings and potentates. Even today, in modern correctional institutions, the penalty of last resort is solitary confinement.

In the past few years, laboratory research has examined the power of our need for contact with others and has, in fact, mapped its physiological roots. Cooperation, for example, activates the "reward" areas of the brain, much as those areas are activated by the satisfaction of hunger. When we confront social rejection, the experience activates the same areas that light up when we are subjected to physical pain. Functional magnetic resonance imaging shows that when we see unfamiliar human beings, or even pictures of human beings, our brains respond in a distinctly different way than they do when we see any other type of object. "Someone like me" is clearly a very important category in our neural wiring. Empathy, too, is traceable: images of humans displaying intense emotions, rather than neutral affect, register in the brain with correspondingly greater intensity. And more significant for where our story will take us, recent studies demonstrate that the social environment can actually modulate RNA transcription, influencing the way cells replicate. Social context also affects immune function.

Despite all the persuasive evidence of our need for connection, and the clear demonstration of the influence of connection on our physiology, there is today a worldwide epidemic of disconnection that until now has been regarded as little different than a personal weakness or a distressing state with no redeeming features. Recent studies have found these notions to be wrong.

To call it an epidemic of loneliness risks having it relegated to the advice columns. Say the word "lonely" and people think dating services, "Miss Lonelihearts," "Only the Lonely," or Los Lonely Boys. But there is nothing trivial, or comical, or poignantly romantic about loneliness. What has emerged is the notion that loneliness is an aversive signal whose purpose is to motivate us to reconnect. But over time if it is not addressed, loneliness can contribute to generalized morbidity and mortality.

Marriage is an imprecise marker of social connection, but the age-adjusted death rate for people who have never been married is 65.9 percent higher than for those who have been married at some time in their lives. Compared to those who are currently married, the age-adjusted death rate for those who never marry is 220 percent higher. Married couples tend also to be less lonely. When one also considers loneliness, much of the health protective effects of marriage disappear.

A generation ago, depression was poorly understood, woefully under diagnosed (it still is) and all too readily dismissed as moodiness or weakness. Most saw it as a character flaw rather than an as an illness.

Now we know that depression is a medical condition with physical manifestations in the brain, that it is to some extent genetic, and that it costs an estimated $44 billion in lost productivity each year for the U.S. economy. Neglected in that impersonal statistic, of course, is a vast amount of human suffering and unfulfilled human potential.

Loneliness is far more than a social misfortune, it is a significant problem of health and happiness that is distinct from but contributes to the likelihood of depression. In a forthcoming blog, we'll examine the relationship between loneliness and depression more closely.

A guy opens the front door and sees a snail on his doorstep. He picks up the snail and throws it across the street in a neighbor's yard. A year later, the guy opens the front door and the same snail is on his doorstep. The snail says, "What the f*ck was that about?"