Almost all of us have experienced loneliness at some point.
It is the pain we have felt following a breakup, perhaps the loss of a loved one, or a move away from home. We are vulnerable to feeling lonely at any point in our lives.
The unpleasant feelings of loneliness are subjective; researchers have found loneliness is not about the amount of time one spends with other people or alone. It is related more to quality of relationships, rather than quantity. A lonely person feels that he or she is not understood by others, and may not think they hold meaningful relationships.
For some people, loneliness may be temporary and easily relieved (such as a close friend moving away, or a spouse returning home after a work trip). For others, loneliness cannot be easily resolved (such as the death of a loved one or the breakup of a marriage) and can persist when one does not have access to people to connect with.
From an evolutionary point of view, our reliance on social groups has ensured our survival as a species. Hence loneliness can be seen as a signal to connect with others. This makes it little different to hunger, thirst or physical pain, which signal the need to eat, drink or seek medical attention.
In affluent modern societies, however, turning off the alarm signals for loneliness has become more difficult than satisfying hunger, thirst or the need to see the doctor. For those who are not surrounded by people who care for them, loneliness can persist.
Researchers have found social isolation is a risk factor for disease and premature death. Findings from a recent review of multiple studies indicated that a lack of social connection poses a similar risk of early death to physical indicators such as obesity.
Some individuals may also be biologically vulnerable to feeling lonely. Evidence from twin studies found that loneliness may be partly heritable.
Multiple studies have focused on how loneliness can be a result of certain gene types combined with particular social or environmental factors (such as parental support).
Loneliness has largely been ignored as a condition of concern in mental health. Researchers have yet to fully understand the extent of how loneliness affects mental health. Most studies of loneliness and mental health have focused solely on how loneliness relates to depression.