If you are a person in the world (or if you've started Season 2 of Master of None), you probably know how it feels to be lonely. You'll know that most things, mundane or otherwise—eating, texting, Netflix—feel less satisfying when you're socially unfulfilled. Now sleep can be added to that list, according to a study published yesterday which found that lonely people tend to report worse sleep quality.
A team from King's College London studied more than 2,200 British identical twins born between 1994 and 1995, for a nationally representative sample of young adults. They defined loneliness as a feeling of inadequate social connection and they differentiated loneliness from social isolation—that is, just like every after-school special hammered into you, being lonely isn't the same as being alone. Overall, their results showed that lonely people were 24 percent more likely to report poor sleep, along with difficulty concentrating during the day.
To reach that result, the authors compiled loneliness scores for each participant using both in-home interviews and a self-completed questionnaire covering feelings of companionship, being left out, isolated, and alone. Overall, 25 to 30 percent of participants reported feeling lonely some of the time, and 5 percent reported frequent feelings of loneliness. The team then went on to measure participants' sleep quality using a second questionnaire that covered everything from typical number of hours' sleep a night, to sleep medications, and daytime problems related to poor sleep.
The analysis also took into account participants' social isolation, employment status, and whether or not they were a parent to a young child. They controlled for depression, anxiety, alcohol use, ADHD, and PTSD, which also have well-documented effects on sleep. Finally, since this was a monozygotic (that is, identical) twin study, the authors analyzed whether genes were responsible for the link, or whether the childhood setting shared by twins introduced a confounding environmental factor. The analysis found that genes weren't a likely culprit, and that loneliness and sleep quality don't seem to share a common genetic origin.
With all the biological and social factors accounted for, the association between loneliness and sleep was still robust. In fact, in one subgroup of participants, the correlation was even stronger: people who had experienced violence, victimization, or maltreatment as children or teens were more likely to experience loneliness and poor sleep. (Examples of victimization in the study included internet harassment, sexual abuse, neglect, trauma, and being a victim of violence.)
The authors chalk up their results to evolution; they suggest that loneliness is fundamentally about not feeling safe. Being cut off from our social groups makes us feel vulnerable, and triggers a fight-or-flight response, or a state of hypervigilance that is essentially incompatible with a good night's sleep. And the authors are not alone in that conclusion—over a decade of research has looked at the possible evolutionary origins of loneliness and its impact on our behavior.
But evo-psych claims aside, there are those who'd like to argue this study is pathologizing an otherwise "natural" feeling. Feeling lonely is so ubiquitous that it's normal, right? But it's refreshing to see researchers take loneliness seriously, given just how much it affects our health. In older adults, loneliness is linked with higher blood pressure, depression, and overall declines in physical and mental health. In fact, most loneliness research has focused on older adults, given the high rates of social isolation in that age group. But according to the UK's Mental Health Foundation, loneliness is actually most frequent in people aged 18 to 34. What's more, chronic feelings of loneliness are quite common—which makes it even more important to recognize the health effects of loneliness in young people, who are more likely to experience chronic social disconnection early in life, leading to worse health over time.
And while sleep quality may not seem like a huge deal if you're young and used to pulling all-nighters, its effects can have a long-standing impact. In their conclusion, the authors write: "Diminished sleep quality is one of the many ways in which loneliness gets 'under the skin', and our findings underscore the importance of early intervention to reduce loneliness in young people." Those interventions include CBT-like strategies to resolve a person's negative beliefs about social situations, beliefs which tend to perpetuate damaging social interactions.
If there's any lesson here, it's that feeling lonely is not your fault. That's particularly true for people who've experienced trauma or abuse, and who are at an even higher risk for loneliness and its negative effects on wellbeing. The good news is, new psychotherapies are looking into ways of helping people feel less lonely—and they might even give you a better night's sleep.
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