Scientists have revealed the terrifying truth about loneliness

An international team of scientists has found that loneliness affects not only mood, but also personality, brain function, immune system, and even dreams. The work is published in the journal Nature Human Behaviour (NHB).

Loneliness is increasingly being described not just as an unpleasant feeling, but as a factor capable of changing a person from within. New research shows that prolonged social isolation affects not only mood, but also personality traits, physiology, and even how the brain processes social information.

Large surveys of elderly people in the US have shown that those who constantly feel lonely become less sociable, less disciplined, and more anxious over time. Scientists note that the changes affect basic character traits, not just current mood.

Other studies link loneliness with emotional instability and negative self-esteem: such people more often perceive themselves as a burden to their loved ones. At the physiological level, loneliness is accompanied by changes in the levels of proteins involved in immune responses and inflammatory processes. This can increase the risk of cardiovascular diseases and diabetes.

The influence of loneliness is felt even in sleep: according to American psychologists, lonely people more often have nightmares, and their rest is less restorative. Neuroimaging studies show that the brains of such people react differently to familiar people and even to fictional characters. In some cases, the boundary between real and "pseudo-social" connections becomes blurred, and the brain processes friends and television characters almost identically.

Adolescents are particularly vulnerable: results of long-term observations of more than 11,000 people in the US showed that loneliness at age 15 significantly increases the risk of depression and post-traumatic stress disorder in adulthood.

Scientists note that loneliness cannot be viewed as a simple absence of company. It is a complex and multi-level experience that gradually changes how a person feels, thinks, and interacts with the world.