A complete lack of sleep is associated with a neural and behavioural profile of social withdrawal and loneliness according to a study involving 18 participants published in Nature Communications.

Matthew Walker and Eti Ben Simon enrolled 18 healthy adults to a sleep laboratory where participants were deprived of one night’s complete sleep. When evaluated on psychological tests of sociability, sleep-deprived subjects avoided other people. Sleep deprivation also led to hypersensitivity in brain regions that warn of human approach. In addition, the sleep-deprived subjects were rated as more lonely when evaluated using video footage by 1,033 independent participants. Moreover, the independent participants rated themselves as feeling significantly lonelier after watching video footage of the sleep-deprived individuals. These results suggest that a lack of sleep leads individuals to keep greater social distance from others, and may possibly make those who come into contact with someone who is sleep-deprived feel lonelier as well.

Although further experiments are needed to see if these associations may change as a function of sex or age across lifespan, these results suggest there may be a relationship between sleep and feelings of loneliness.