The association between cosleeping and emotional-behavioral problems differs depending on the presence of sleep anxiety in preschool children: cosleeping is linked to fewer emotional-behavioral problems for children with sleep anxiety, whereas it is associated with more emotional-behavioral problems for children without sleep anxiety.
Key Findings
Results
Cosleeping was highly prevalent among preschool children in the Shanghai cohort, with 75.7% of children practicing cosleeping at baseline.
A total of 15,679 children were included in the final analysis after excluding invalid data from an initial recruitment of 20,899.
8,082 boys (51.5%) and 7,597 girls (48.5%) were included.
Mean age at first survey was (3.73±0.29) years.
11,872 of 15,679 children (75.7%) practiced cosleeping at the first survey.
Data were drawn from the SCHEDULE-P prospective cohort across 191 kindergartens in Shanghai, with follow-up surveys in April 2018 and April 2019.
Results
Overall, preschool children who practiced cosleeping had a higher risk of emotional-behavioral problems compared with those who slept independently.
OR=1.12, 95% CI 1.03–1.21, P=0.006 in mixed-effects Logistic regression models.
The elevated risk was particularly present in the domains of emotional problems, hyperactivity problems, and prosocial behavior problems (all P<0.01).
Emotional-behavioral problems were assessed using the Strengths and Difficulties Questionnaire (SDQ), covering emotional problems, conduct problems, hyperactivity problems, peer relationship problems, and prosocial behavior problems.
Results
Sleep anxiety significantly moderated the association between cosleeping and emotional-behavioral problems across all SDQ domains.
The moderation model indicated statistically significant interaction effects between cosleeping and sleep anxiety on the total SDQ score and all subscales (all P<0.01).
Sleep anxiety was assessed using the sleep anxiety subscale of the Children's Sleep Habits Questionnaire (CSHQ).
Cosleeping status was assessed via the question 'Does the child sleep alone in their own bed?' from the CSHQ.
Results
Among children with sleep anxiety, cosleeping was associated with lower risks of emotional-behavioral problems overall, particularly in peer relationship and conduct problem domains.
OR=0.87, 95% CI 0.77–0.99, P=0.033 for total emotional-behavioral problems among children with sleep anxiety who coslept versus those who did not cosleep.
Specifically, peer relationship problems and conduct problems were both significantly lower in cosleeping children with sleep anxiety (both P<0.05).
This finding was obtained through stratified analysis dividing children into two groups based on the presence or absence of sleep anxiety.
Results
Among children without sleep anxiety, cosleeping was associated with higher risks of peer interaction and prosocial behavior problems.
Both peer interaction problems and prosocial behavior problems were significantly elevated in cosleeping children without sleep anxiety compared with non-cosleeping children without sleep anxiety (both P<0.05).
This contrasts with the protective pattern observed in children with sleep anxiety.
The direction of the cosleeping-emotional/behavioral problem association was opposite depending on whether sleep anxiety was present.
What This Means
This research suggests that the relationship between children sharing a bed or sleeping space with their parents (cosleeping) and children's emotional and behavioral development is not straightforward—it depends heavily on whether the child experiences sleep anxiety. The study followed nearly 16,000 preschool-aged children in Shanghai over several years, finding that about three-quarters of them coslept with their parents. Overall, cosleeping was linked to a slightly higher chance of having emotional and behavioral difficulties, particularly in areas like emotional regulation, hyperactivity, and social behavior. However, when researchers accounted for whether children had sleep anxiety, the picture changed dramatically.
For children who experienced sleep anxiety—meaning they were fearful or anxious around bedtime and sleep—cosleeping was actually associated with fewer behavioral and emotional problems, especially fewer difficulties with peer relationships and conduct. This suggests that for anxious children, the closeness and reassurance of sleeping near a caregiver may buffer against developing behavioral problems. In contrast, for children who did not have sleep anxiety, cosleeping was linked to more difficulties in peer interactions and prosocial behaviors (like sharing or cooperating), possibly because these children miss out on developing independence and self-soothing skills they would otherwise practice sleeping alone.
This research suggests that decisions about cosleeping should take into account a child's individual temperament and anxiety levels rather than applying a one-size-fits-all approach. For families and pediatric care providers, understanding whether a child has sleep-related anxiety may help clarify whether cosleeping is likely to be helpful or potentially associated with more behavioral challenges for that particular child.
Wang Y, Zhou M, Ma X, Jiang Y, Lin Q, Jiang F. (2026). [Association between cosleeping and emotional-behavioral problems and its differences with or without sleep anxiety in preschool children].. Zhonghua er ke za zhi = Chinese journal of pediatrics. https://doi.org/10.3760/cma.j.cn112140-20251103-00983