Bed-Sharing in Couples Is Associated With Increased and Stabilized REM Sleep and Sleep-Stage Synchronization

Abstract

Background/Objectives: Sharing the bed with a partner is common among adults and impacts sleep quality with potential implications for mental health. However, hitherto findings are contradictory and particularly polysomnographic data on co-sleeping couples are extremely rare. The present study aimed to investigate the effects of a bed partner's presence on individual and dyadic sleep neurophysiology. Methods: Young healthy heterosexual couples underwent sleep-lab-based polysomnography of two sleeping arrangements: individual sleep and co-sleep. Individual and dyadic sleep parameters (i.e., synchronization of sleep stages) were collected. The latter were assessed using cross-recurrence quantification analysis. Additionally, subjective sleep quality, relationship characteristics, and chronotype were monitored. Data were analyzed comparing co-sleep vs. individual sleep. Interaction effects of the sleeping arrangement with gender, chronotype, or relationship characteristics were moreover tested.

Couple Relationships Are Associated With Increased REM Sleep—A Proof-of-Concept Analysis of a Large Dataset Using Ambulatory Polysomnography

“…Thus, the here presented findings indicate a generalizable promoting effect of couple relationships on REM sleep. Thereby, the present work represents a necessary (but not sufficient) condition regarding the implications of the partner-related REM-sleep increase as proposed by Drews and colleagues (13,33). These potential implications are, first, REM sleep acts as a mechanism through which close social relationships benefit mental health: Disrupted REM sleep has been argued to cause insomnia (2, 3), which in turn increases the risk for mental illnesses (e.g., mood disorders) (38).…”

“…Additionally, the homogeneity of the samples regarding young age, health status, and ethnicity make the results of the previous studies less generalizable to the general population. These weaknesses have been discussed previously (13).…”

“…Second, the present work compares married individuals to never married individuals which means that the actual sleeping arrangement (bed-sharing vs. individual sleep) remains unknown. This could be seen as impairing comparability with the aforementioned studies on co-sleeping that directly manipulate the sleeping arrangement (13,14,33). Yet, it is of note that there is a high correlation between the marital statuses and sleeping arrangement: In the US ≥87% of the married individuals share a bed with their partner (18) (this number might be lower in elderly couples) and <5% of the elderly population (aged 50 and above, which is comparable to the present sample) are cohabiting (and co-sleeping) while not being married (17).…”

“…However, there are ambiguities between the present work and these previous studies on co-sleeping couples that concern the microstructural correlates of the increase in total REM sleep when sleeping with a partner. Drews and colleagues (13) report decreased fragmentation of REM sleep, a non-significant decrease sleep stages N1-N3 (p-values between 0.26 and 0.5), and a non-significant (counterintuitive) increase in awakenings FIGURE 2 | REM sleep duration in married and never married individuals. Absolute (A) and relative (B) REM sleep duration is significantly higher in married individuals (blue raincloud plots) than in never married individuals (red raincloud plots): 76.5 ± 27.7 min vs. 62.9 ± 33.1 min, p = 0.003; and 20.5 ± 6.2% vs. 17.1 ± 7.7% p = 0.001.…”

Connecting sleep, the neurocognitive memory system, and Bourdieu's habitus concept: Is sleep a generative force of the habitus?

“…Sleep is rarely included in sociological theories. This is somewhat surprising given the emerging evidence that sleep is significantly influenced by social and cultural contexts (Brunt & Steger, 2008; Drews et al, 2017, 2020; Grandner, 2017) and is crucial for social and societal functioning (e.g., Diekelmann, Paulus, & Krach, 2018; Drews et al., 2018; Simon & Walker, 2018; Wheaton, Chapman, & Croft, 2016). Moreover, sleep has been shown to play an important role in several core processes of human cognition and behavior including decision making (Harrison & Horne, 2000), delinquent behavior (Meldrum, Barnes, & Hay, 2015), memory formation (Diekelmann & Born, 2010), emotion regulation (Palmer & Alfano, 2017), and many more.…”