The quality of a person’s romantic relationship in early adulthood is linked to their sleep quality in middle adulthood, according to a new Personal Relationships study. The research helps explain why people with higher-quality relationships tend to have better health.

“Decades of research has shown that close relationships can have significant impacts on people’s health. However, the explanations for how relationships impact health are still murky. One way in which relationships can affect health is by affecting people’s sleep,” said Chloe Huelsnitz, a PhD candidate at the University of Minnesota and the corresponding author of the new study.

“We were interested in looking at the ways in which people’s relationships (and their stress) can affect their sleep because sleep is a particularly unique health behavior in that many people in romantic relationships regularly sleep with their partner (e.g., co-sleeping). Thus, romantic partners should be a strong source of influence on this behavior.”

The researchers analyzed data from 112 mothers who participated in the Minnesota Longitudinal Study of Risk and Adaptation.

The women were recruited in 1975–1976 and the quality of their romantic relationships were assessed at ages 23 and 32. Their sleep quality and duration were assessed at age 37. At all three time points, the participants reported stressful life events that had occurred during the preceding year.

Huelsnitz and her colleagues found that participants with better relationships at age 23 tended to experience fewer stressful life events at age 32, which in turn predict better sleep quality at age 37.

“The takeaway is that your romantic relationships can affect your sleep by affecting the stressful events you experience. In other words, people who have a history of higher quality relationships experience fewer stressors over time, which leads them to have better sleep,” Huelsnitz told PsyPost.

The researchers controlled for the potential effects of depressive symptoms, sex, ethnicity, income, education, and maternal education. But like all research, the study includes some caveats.

“The primary caveat is that this study is correlational, meaning that we cannot conclude that being in a higher quality relationship causes people to experience fewer stressors. It could be the case that there are other factors that lead people to being in a higher quality relationship and experience fewer stressors,” Huelsnitz said.

“However, we did statistically control for other factors that could make a difference, and the results are the same.”

The study, “The interplay between relationship effectiveness, life stress, and sleep: A prospective study“, was authored by Chloe O. Huelsnitz, Jeffry A. Simpson, Alexander J. Rothman, and Michelle M. Englund.

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