Loneliness may rob you of your sleep, British researchers report.
In the study, more than 2,200 18- and 19-year-olds in England and Wales provided information about their loneliness levels and sleeping patterns.
Between 25 percent and 30 percent of the participants said they felt lonely sometimes, and another 5 percent said they frequently felt lonely.
Lonelier people were 24 percent more likely to feel tired and have difficulty concentrating during the day, according to the King's College London researchers.
"Diminished sleep quality is one of the many ways in which loneliness gets under the skin, and our findings underscore the importance of early therapeutic approaches to target the negative thoughts and perceptions that can make loneliness a vicious cycle," said study author Louise Arseneault.
"Many of the young people in our study are currently at university, living away from home for the first time, which can compound feelings of loneliness. It is therefore important that they receive appropriate support to address these feelings before they turn into severe mental health problems," she said in a college news release.
Arseneault is with the school's Institute of Psychiatry, Psychology & Neuroscience.
The link between loneliness and sleep quality remained even after the researchers accounted for depression and anxiety, which are commonly associated with sleep problems and feeling lonely. But the study did not prove that loneliness causes lost sleep.
It's been suggested that restless sleep in lonely people can be due to feeling less safe, so the study authors examined the impact of past exposure to violence, including crime, sexual abuse, child abuse and violent abuse.
The connection between loneliness and poor sleep quality was almost 70 percent stronger among those who'd experienced the most severe forms of violence.
Study co-author Timothy Matthews is also a researcher at the institute. "Past exposure to violence exacerbated the association between loneliness and poor sleep, which is consistent with the suggestion that sleep problems in lonely individuals are related to feeling unsafe," he said in the news release.
"This makes sense as sleep is a state in which it is impossible to be vigilant for one's safety, so feeling isolated from others could make it more difficult to sleep restfully, and even more so for individuals who have been exposed to violence in the past," Matthews explained.
"It is therefore important to recognize that loneliness may interact with preexisting vulnerabilities in some people, and that these individuals should receive tailored support," he said.
The study was published recently in the journal Psychological Medicine.