Bed-Sharing in Couples Is Associated With Increased and Stabilized REM Sleep and Sleep-Stage Synchronization.
Level 3 - non-randomized controlled study
Within-subject comparative crossover study with objective polysomnography; randomization of condition order not specified in abstract.
PubMed 32670111 · doi:10.3389/fpsyt.2020.00583
What was done
Young healthy heterosexual couples underwent sleep-laboratory polysomnography under two conditions: individual sleep and co-sleeping. Researchers measured individual sleep parameters, limb movements, and dyadic sleep-stage synchronization (via cross-recurrence quantification analysis). Subjective sleep quality, chronotype, and relationship characteristics (such as social support and relationship depth) were assessed to examine interaction effects with sleeping arrangements.
What was found
Compared to individual sleep, co-sleeping resulted in: - Approximately 10% more REM sleep - Less fragmented REM sleep (p = 0.008) and longer undisturbed REM fragments (p = 0.0006) - More limb movements (p = 0.007) - No significant alterations in other non-REM sleep stages - Significantly greater sleep-stage synchronization between partners (p = 0.005; p = 0.022 with wake phases excluded), coupled across a ±5-minute lag - A larger REM increase in individuals reporting suboptimal social support, and a positive main effect of relationship depth on dyadic synchronization - No significant moderating effects of gender or chronotype.
Why it matters
This study provides objective polysomnographic evidence that bed-sharing alters sleep architecture by stabilizing and enhancing REM sleep while promoting physiological sleep-stage synchronization between partners.
Limits
The abstract does not report the sample size (n), counterbalancing, or whether the sequence of sleeping conditions was randomized. The findings are restricted to young, healthy heterosexual couples in an unfamiliar laboratory environment and may not generalize to older adults, clinical populations with sleep disorders, non-heterosexual couples, or natural home sleeping settings.
Cited by
- context People generally experience worse sleep when sharing a bed with a partner compared to sleeping alone.
- partial Data show that individuals generally do not sleep as well when sharing a bed with a partner compared to sleeping alone.