The 2-Way Street Between Loneliness And Sleep That’s A Very Big Deal For Your Health

The 2-way street between loneliness and sleep that’s a very big deal for your health

If you’re a regular reader here (and I hope you are!), you’ve heard me talk in recent weeks (including with Gail King on The CBS Early Show and others) about a new study that points to poor sleep as a cause of loneliness and social isolation.

This is a fascinating study. It’s also big news for all of us who care about sleep, and how improving sleep can help us live better, fuller, healthier lives.

We’ve got a big problem with loneliness and social isolation in the U.S. and elsewhere today. And sleep plays a major role. Let’s take a closer look at the impact of loneliness and social isolation mental and physical health, and the emerging two-way street between sleep and loneliness.

As a society, we’re increasingly lonely and more sleep deprived

We all have moments when we experience loneliness and feel disconnected from others around us. It can happen when you’re actually alone, but also when you’re in a crowd of strangers, or when you’re surrounded by people you know well.

But more of us than ever appear to exist in ongoing states of loneliness and social isolation. And it’s those chronic conditions of loneliness that are particularly worrisome, and dangerous to our health.

Over the past several years, chronic loneliness and social isolation have become recognized as a serious public health issue, talked about as a health risk on par with or even more dangerous than smoking and obesity. The healthcare company Cigna recently reported results of a survey showing epidemic levels of loneliness, with almost half of adults in the U.S. report regularly or always feeling alone or left out. More than 1 in 4 adults reported they rarely, or never feel understood by other people.

Estimating the prevalence of loneliness and social isolation is tricky. But demographic data indicate that both have been on the rise for decades. Studies show a 10 percent increase in US adults living alone, along with fewer people getting married and having children. Beyond family connections, research shows that fewer of us volunteer, attend church, and participate in social groups. And the average size of our social networks has dropped by a third over the past 20-30 years.

Over roughly the same time period, we’ve seen a worrisome rise in sleep problems and sleep complaints, and a decline in the average duration of nightly rest. According to the Centers for Disease Control, more than a third of working U.S. adults sleep no more than 6 hours a night. And somewhere between 50-70 million people in the U.S. suffer with a sleep disorder.

What does it mean to be lonely or socially isolated?

At first glance, this might seem like a simple question to answer. In fact, it’s not.

Loneliness and social isolation are often spoken about together. But though they’re often related, they’re not the same thing.

Loneliness is a subjective feeling, of lacking in connection and companionship, of an absence of belonging. Loneliness can also include feelings of disappointment in the quality of relationships with friends and family.

Social isolation is an objective state, in which a person has limited social contacts, a lack of social engagement, and a deficit of meaningful, fulfilling relationships. Social isolation can, and often does, create loneliness. But feelings of loneliness are entirely possible among people who are not socially isolated—that is, people who have many friends, a large family, or a robust social life can still experience deep and chronic loneliness. And people who live relatively solitary lives, with low levels of social engagement, don’t always or automatically feel loneliness.

In recent years, we’ve also learned that there is a physiological state that accompanies loneliness. Loneliness alters the way the body functions at a cellular and genetic level. Loneliness, researchers are now discovering, directly affects our biology in ways that put us at greater risk for illness and disease. (I’ll talk more about this in a minute.)

And as this newest study on loneliness and sleep shows, there’s a viral quality to loneliness.

It’s important to know that loneliness and social isolation can develop in any one of us. All of us experience moments or periods of loneliness, when we long for more connection and companionship. We’re all also apt to go through distinct and temporary periods of social isolation, which may be linked to life changes such as a move, the loss of a job, a divorce, illness of our own or of a loved one, or children leaving home.

Episodes of loneliness are common, as we react and respond to circumstances and changes in our lives. In many people, episodic loneliness can linger and eventually become chronic. And it’s chronic loneliness and social isolation that’s associated with some serious health risks.

The health risks of being lonely and socially isolated

The relationship between loneliness and health has for years been of increasing interest to scientists. There’s a large and growing body of research that shows loneliness and social isolation significant increase our risks for premature death. An important study from 2015, conducted by scientists at Brigham Young University, found that our risks of early mortality increase 26 percent with loneliness, 29 percent with social isolation, and 32 percent with living alone. Other recent research shows loneliness increases mortality risks by 45 percent.

Loneliness and social isolation have been linked to an alarming list of specific health hazards. As you’ll see, each and every one of these health risks is also associated with poor sleep.

Cardiovascular disease. Loneliness and social isolation contribute to high blood pressure, as well as to hardening of the arteries, and to poor circulation. Risks for both heart attack and stroke are higher among people who are lonely and less socially engaged.

Healthy sleep is critical for heart health—and poor sleep raises risks for heart disease, stroke, and high blood pressure.

Obesity. The risk of obesity rises among people who are lonely or socially isolated. There is some fascinating, brand-new research that indicates a genetic link between obesity and loneliness. In a study of more than 450,000 individuals, scientists found people who were lonely and people who were overweight shared similar genetic variations. They also found specific genetic variations were more likely to be found in people who were highly socially engaged. We’ve known for some time that there’s a strong genetic component to obesity. This new research suggests there’s a genetic component to loneliness as well—and that the two conditions may share similar genetic roots.

Sleep has significant effects on our weight and risk for obesity, via its influence over our hunger hormones, our appetites, and our energy expenditure.

Suicide. Loneliness is linked to depression and anxiety as well as to greater risk for suicidal thoughts. The presence of loneliness increases risks for suicidal behaviors, especially in people with mental health conditions.

I wrote this summer about the powerful, overlooked relationship between suicide and sleep.

Immune dysfunction. What we’re learning about the impact of loneliness and social isolation on the immune system is pretty game changing. Loneliness and social isolation bring about changes to the way the immune system functions, and how it responds to threats. Specifically, in people who are lonely their immune systems are highly active and on alert to fight against bacterial threats. This focus on bacterial invaders leaves the immune system less able to mount effective defense against viral threats and other diseases. This, scientists believe, is one reason why lonely people are more vulnerable to chronic disease and early death.

Loneliness also elevates the body’s stress hormones, including cortisol, and inflammation.

Sleep itself plays a critical role in immune health, strengthening the body’s ability to fight illness and disease. Poor quality and insufficient sleep compromise healthy immune function and can trigger unhealthful inflammation.

Cognitive health. Historically, a lot of research into loneliness and social isolation has focused on older adults. (That’s changing, but we still need more attention to understanding the effects of loneliness throughout a lifetime.) In studies of older adults, scientists have found evidence that loneliness and social isolation contribute to cognitive dysfunction and accelerated cognitive decline. Research shows loneliness is associated with accumulation of amyloid protein the brain. Amyloid protein build-up is a key sign of Alzheimer’s disease. Other research has shown loneliness in adults over 50 is linked to accelerated cognitive decline.

Sleep is essential for our brains to function at their best, for decision making, learning, and memory. Poor sleep is linked to cognitive impairment, and cognitive decline with age. And, as I wrote about recently, there’s fast-accumulating evidence that poor sleep increases risks for Alzheimer’s and other neurodegenerative diseases.

How loneliness can wreck sleep

The news that sleep can make us more lonely is hot off the press. But we’ve known for some time that loneliness and social isolation interfere with sound, plentiful sleep. There’s a body of research showing being lonely reduces sleep quality and sleep efficiency (that’s a measurement of the quality of sleep, based on the amount of time you spend in bed relative to the amount of time you spend actually sleeping).

Studies show the quality of our friendships actually predict how well we sleep. The stronger, more meaningful and intimate our friendships are, the better sleepers we can be.

If you’ve been following our ongoing conversation about bio rhythms and bio time, you know that there’s a link between sleep and almost everything we do when we’re awake. Remember, the same bio rhythms that regulate our sleep also govern everything from appetite to sex drive, and give us innate, biological preferences for when we work, relax, and socialize. Research shows that good sleepers tend to be people who are more regularly engaged in social activities.

(How much do you know about your individual bio rhythms? Find your chronotype by taking my quiz at

Loneliness also increases stress, which in turn can undermine and disrupt sleep. Loneliness contributes to spikes in cortisol, and higher levels of cortisol can mean trouble falling asleep, and a tendency to wake more frequently throughout the night. Increasingly, we’re learning that the brain and the body respond to loneliness and social isolation as a threat, similar to the way it would to a potentially harmful pathogen, or a predator. Loneliness appears to create a state of vigilance and high alert that can interfere with our ability relax and rest soundly.

Lack of sleep makes us lonely and withdrawn—and spreads loneliness to others

This new research from scientists at University of California, Berkeley is the first to show that the sleep-loneliness connection really is a two-way street. We already knew loneliness interfered with sleep. This study shows that sleep can actually trigger loneliness and social isolation.

In a series of experiments, sleep scientists observed how lack of sleep led changes in behavior, emotion, and brain activity, all related to loneliness and social estrangement. They found:

  • Lack of sleep corresponded to heightened feelings of loneliness, from one day to the next.
  • Sleep deprived people were more withdrawn, avoiding social contact in ways similar to people with anxiety.
  • In the brains of sleep deprived people, areas responsible for understanding other people’s actions became less active. At the same time, areas of the brain responsible for signaling warnings about other people getting too close became more active.

The sleep scientists also looked at how exposure to sleep-deprived people affected other people’s perceptions and feelings. They found:

  • Sleep-deprived people were perceived as lonely, and also as less socially attractive by others.
  • After observing people who were sleep deprived, others felt similar feelings of loneliness and alienation themselves—even though they were rested and healthy.

That’s the viral component to sleep-induced loneliness that is so striking and significant. Sleep deprivation made people feel more lonely and socially withdrawn, and made others want to avoid social interaction with them, which in a real-world setting would only compound a person’s loneliness. But the impact went beyond even that: sleep-loss induced loneliness in one person made other people feel lonely and alienated, too.

It’s past time for us to start considering loneliness and social isolation as the pressing health threats they are. Establishing, maintaining, and deepening social connection throughout our lives is another fundamental pillar of wellness, as important as eating well, exercising, and sleeping. As with so many other aspects of our lives, sleep can play an essential, constructive role in helping us engage with others, and feel a sense of belonging in our families, with our friends, and in our communities.

Sweet Dreams,

Michael J. Breus, PhD, DABSM

The Sleep Doctor™