But if your relationship is fraught with strife, be prepared for long nights spent tossing and turning, new research suggests.
In a study of nearly 3,000 women, those who were in unhappy unions were about 50% more likely to suffer symptoms of insomnia than their happily married counterparts. Unmarried women were about 30% more likely to have trouble sleeping than women in happy unions.
The findings were presented at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies.
Which Comes First: Poor Sleep or Marital Strife?
"There's been a lot of research showing that married women sleep better than divorced women, but not much has been known about whether the status of that marriage affects sleep patterns," says Wendy M. Troxel, PhD, a psychologist at the University of Pittsburgh.
"What we found," she tells WebMD, "is that unhappily married women didn't differ much from unmarried women as far as insomnia goes. It's not marriage per se that is beneficial, it's a happy marriage."
The study leaves open the question of whether marital discord makes it harder to sleep or whether poor sleep can ruin a perfectly good marriage.
Troxel suspects it's the former. "Our hypothesis is that if you have a sense a support, someone with whom to unwind at the end of the day, you'll be less stressed and better able to fall asleep.
"An unhappy marriage, on the other hand, can be a source of stress. It can be harder to fall asleep when you're fighting with someone, particularly if they're lying next to you," she says.
Donna Arand, PhD, a sleep specialist at Kettering Hospital Sleep Disorders Center in Dayton, Ohio, agrees. "We've known for some time now that sleep is impacted by what happens to you during the day. Activities that promote stress and anxiety adversely affect sleep, and marital discord is certainly a major stressor," she tells WebMD.
Happily Married Women Have Fewer Insomnia Symptoms
The study involved 2,970 women, aged 42 to 52, enrolled in the Study of Women's Health Across the Nation. About one-third were happily married, one-third unhappily married, and one-third unmarried.
Out of total, about half were white, 20% were African-American, and 10% each were Hispanic, Chinese, or Japanese.
Compared with those in happy unions, unhappily married and unmarried women were more likely to experience any of four insomnia symptoms at least three times over a two-week period: trouble falling asleep, trouble staying asleep, waking up early, and restless sleep.
When looked at by ethnicity, the results held up in white, African-American, and Hispanic women.
There was a trend toward more restful sleep among happily married Chinese and Japanese women than their unmarried or unhappily married counterparts, but the finding could have been due to chance. "That could be because not enough women were studied, or because of some cultural differences in terms of a woman's role in marriage," Troxel says, adding that further study is needed.
The study also showed that not sleeping through the night was by far the most common complaint among all women who experienced symptoms of insomnia.
Arand says that regardless of the state of your marriage, women who experience persistent symptoms of insomnia for more than three weeks may want to consider seeing a sleep specialist. "Then depending on how much your marriage is impacting sleep, it might make sense to seek marriage counseling at the same time," she says.