Although co-sleeping is associated with sleep disturbances in children, few studies have examined the effect of sharing a bed with an adult partner — even though well over half of the adult population in the United States shares their bed with a significant other.
A 2017 study published in the journal Sleep Disorders set out to determine the effects of co-sleeping on the sleep of heterosexual adult couples. Researchers recruited four adult couples between the ages of 20 and 29 who were:
- In a good relationship (as measured by the Quality of Relationship Inventory)
- Good sleepers (as measured by the Pittsburg Sleep Quality Inventory and the Epworth Sleepiness Scale)
- Co-sleeping for at least six months prior to the study
Each couple slept in a sleep lab for two consecutive nights on two separate occasions. On one occasion, couples slept alone in separate rooms and on the other occasion, couples co-slept. The sleep of participants was recorded using polysomnography.
Is it good to share a bed with your partner?
The short answer is: maybe!
The study found that when couples slept together, total sleep time and sleep efficiency increased significantly. Participants also entered deep sleep (also known as the third stage of sleep) more quickly and reported feeling significantly more relaxed after having co-slept with a partner.
When is it bad to share a bed with your partner?
Interestingly, researchers found that there was a significant synchronization of sleep stages when partners co-slept. Researchers pointed out that although sharing a bed with a healthy sleeper may benefit someone with a sleep disorder, it may be disruptive for a healthy sleeper.
In other words, if your partner is an insomniac but you are not, sharing a bed may be good for them, but bad for you!
The authors of the study also pointed out that all participants were in a good relationship. If you are in a bad relationship, these benefits may no longer apply. In fact, one study found that those who are unhappily married are 50 percent more likely to have insomnia.
Although you may assume that a bed partner who moves around a lot will disturb your sleep, the authors of this study pointed out that previous studies that set out to investigate this used actigraphy, which cannot differentiate between wakefulness and sleep. As a result, it is still unclear how much influence a bed partner’s movements can have on your sleep.
The power of relationships
Being in a happy relationship has been found to be good for your health. It makes sense, therefore, that co-sleeping with a partner can be good for your sleep, too — as long as you are in a happy, healthy relationship.