If anyone dozes off during Neil Stanley’s talks, the sleep expert usually yanks them awake by declaring the unthinkable.

We sleep better when we sleep alone.

Research shows that couples who bed together have 50 per cent more disrupted sleep than those who slumber apart, the British sleep guru tells audiences around the world.

What’s more, he and his wife slept in separate rooms and were none the worse for it.

In other words: save your marriage with a sleep divorce.

“The fact that I sleep separately came out by accident,” he says. “I was forbidden to mention this in interviews.

“We have this huge belief that we should sleep together and any deviation is problematical or indicative that the relationship is threatened,” continues Stanley, who ran a sleep lab at the University of Surrey in the 1990s.

There’s a lot that can go awry when two adults share a mattress. “We compromise about our sleep,” says Stanley, who is 47.

To his point: two adults in a double bed have nine fewer inches per person than a child in single bed, he says. If your partner snores loudly, hogs the blankets or wakes you up with nocturnal needs, the result may be two miserable people. So why not take the practical course and sleep in another room? It’s not banishment.

“It’s all nice to kiss and have a cuddle, but at some point you say, ‘I’m going to sleep now,’ and that means leave me alone,” he says. “Why not at that point go to another room and sleep because that’s what you want to do?”

Many Canadians complain they don’t get enough quality time in bed, but it’s more than simple fatigue — sleep affects overall health and well-being. Reduced sleep is linked to a host of illnesses and conditions, including heart disease, stroke, obesity and, as a study showed last year, more aggressive breast cancer tumours.

About 40 per cent of Canadians are troubled by sleep disorders, a 2011 study at Laval University showed, and 10 per cent of them use prescription drugs to treat the problem. A 12-year study of 14,000 Canadians, also at Laval, showed higher death rates — as much as 36 per cent — for those using sleep or anxiety medication. Tranquilizer and sleeping pill use has also been linked to increased vehicle accidents.

There has never been so much study of and writing about sleep.

About 6,000 sleep experts will attend the annual meeting of the American Academy of Sleep Medicine in June in Baltimore.

There are thousands of books for laypeople, including the recent Dreamland — Adventures in the Strange Science of Sleep (David Randall) and The Slumbering Masses — Sleep, Medicine, and Modern American Life (Matthew Wolf-Meyer). Some are by academics posing new theories and some by sufferers spurred by their own misery.

Of tens of thousands of research papers on sleep — with subjects including preschoolers in Tehran, middle-aged Finns, sleep and hypertension — only 15 address sleeping couples, one researcher found.

Studies in the U.S. and Britain show that about one-quarter of couples regularly sleep separately, though Pittsburg psychologist Wendy Troxel says some 90 per cent of U.S. married couples sleep together. It’s not clear if people truthfully reveal their nighttime activity. “It’s still a taboo subject,” she says.

“Most of us sleep with someone and yet we know very little and the data we have is hardly conclusive,” says Troxel, a researcher at the Rand Corporation, a non-profit think-tank. “So much of what we talk about, the prescriptions and the stigma, how we should and should not sleep, is based on beliefs rather than any science.”

A report from the U.S. National Association of Home Builders predicted that by 2016 more than half of new custom-built houses would have two master bedrooms. Some cited that as evidence that more couples want to sleep apart but Brian Johnston, chief operating officer for Mattamy Homes, Canada’s largest home builder, sees otherwise. “I’d be skeptical if that was a trend,” he says. “There’s a much sounder reason.” Houses with two master bedrooms appeal to new Canadians — more so in the GTA — where several generations live together.

Barely a half-dozen studies have actually measured the way couples sleep, she says. The gold standard for sleep studies dates to 1969, when the brainwaves of couples sleeping together and apart were measured using polysomnography. When the couples slept apart they had more deep, stage-four sleep.

More recent studies use actigraphy, a device that looks like a wristwatch and measures movement at night. They, too, show couples sleep better or, at least, with less movement, when apart.

Despite the evidence, most couples report they are more satisfied with their sleep when they are with their partners. Even though they’ve been shown to be restless, they want to believe they have slept better.

As Troxel wrote in a recent paper: “The psychological need for closeness and security, particularly at night, trumps the equally important need for good-quality sleep.”

Josey Vogels, a sex-and-relationships columnist and blogger, went public last year writing that she and her husband, photographer Daniel Parker, sometimes sleep separately. It was one of her most polarizing columns, she says.

Theirs are the usual husband and wife differences in bedroom comfort: she likes a cool room, he likes it warm; she’s a light sleeper who tosses and turns when worrying about something, he’s a light snorer. All conspire against a restful night.

(For a woman, sensitivity to light and inclination to worry are among the factors that predispose one to insomnia, a 2012 review of the effect of bed partners on sleep by psychologists at Ryerson University showed.)

“When I end up getting a good night’s sleep, I’m much happier to see him in the morning and less resentful and less exhausted,” says Vogels, 48.

“There’s something about the marital bed, that it’s some sacred thing,” she says. “But it was a relief to come out of the closet . . . and oppose conventional wisdom that if you’re not sleeping together, there’s something wrong.”

Paul Rosenblatt’s curiosity about everyday life led him to interview 88 adults about their sleep. A University of Minnesota professor emeritus in psychology, Rosenblatt reported his findings in the ebook Two in a Bed: The Social System of Couple Bed Sharing.

Women felt safer sleeping with their partner — he describes it as the “awesome power of being close to another human being” — even though they slept less well, he learned. “For most people there is this feeling of intimacy, this is where we should be. We are a couple and this is a symbol of our completeness.”

He found five couples who said one partner was alive because the other was in bed and helped in a medical emergency, such as diabetic shock. Others said the few minutes before sleep were sometimes the only time to talk about their day.

Older couples are more likely to sleep apart, often because as kids move out, bedrooms are freed up. “One couple said, ‘We are fine sleeping apart, but when our kids are home, we have to pretend to sleep together.’ ” The kids thought the relationship was in trouble if Mom and Dad weren’t in the same bed.

More men than women regretted sleeping apart because it reduced opportunities for sex, Rosenblatt found.

An older woman told him: “I don’t want to be awakened at night to have sex. I’ve served my time.” Then he asked the husband if he missed his wife’s company.

He replied: “No. I miss the nookie.”

As for that, we were curious about sleep expert Stanley and his assertion that separate bedrooms do not dampen the spark of love. His online bio describe the beds he and his wife use, that he wears cotton pyjamas and that he needs nine hours’ sleep. And he insists there’s nothing wrong with “you have your bedroom and I have mine.”

How are things going, we asked. Sadly, it was not what we expected:

“We are divorced. But it (sleeping apart) was not a contributory factor to the divorce.”