A large study of mother-child pairs in Singapore has found that higher maternal depression scores and better maternal sleep quality are linked to longer infant sleep durations. This counters long-held assumptions that poor maternal mental health negatively affects infant sleep, suggesting the need to rethink approaches to supporting new mothers. The findings were published in the journal European Child & Adolescent Psychiatry.
The study, conducted using data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort, followed 1,131 mother-infant pairs from the prenatal period through the child’s second birthday. Researchers aimed to determine the direction of influence between infant sleep, maternal sleep, and maternal depressive symptoms, using a rigorous statistical model that distinguishes between changes within individuals over time and general differences between people.
Earlier research has often relied on methods that blur these lines, potentially misattributing cause and effect. In contrast, this study used a sophisticated modelling technique known as ALT-SR, which revealed a striking pattern. Higher maternal depression scores at three months predicted longer child nighttime sleep at twelve months, while better maternal sleep at three months also forecasted longer sleep durations in infants at one year.
The results also indicated that infant sleep did not predict later changes in maternal depression or sleep, challenging previous findings based on traditional statistical methods. When the team tested those older models, the supposed negative influence of maternal depression on infant sleep was no longer supported.
While the findings are unexpected, the authors caution against overinterpreting them. Most mothers in the study showed mild or no clinical depression, meaning the results may not apply to more severe cases. Nonetheless, the study highlights the importance of using precise methods when investigating complex interactions in early parenthood.
Cultural practices in Singapore may also have played a role in shaping the results. Practices such as co-sleeping, extended breastfeeding, and the involvement of grandparents or domestic helpers are common, potentially alleviating some of the burdens that might otherwise worsen maternal mental health. However, the study found no clear links between non-maternal night-time caregiving or co-sleeping and better outcomes for either mothers or infants.
Interestingly, breastfeeding appeared to have a dual role. At three months, it was associated with shorter infant sleep and slightly higher maternal depression scores. But by twelve months, continued breastfeeding was linked to longer infant sleep and lower maternal depression scores, suggesting a more nuanced relationship than previously thought.
Despite some limitations, including reliance on maternal self-reports and missing data for certain caregiving variables, the study offers a compelling call to re-evaluate existing assumptions. It also underscores the need to consider cultural context and statistical precision in research on maternal and infant health.
As researchers and health professionals continue to explore how best to support families during the early years, these findings suggest that maternal well-being may not be as fragile a foundation for infant sleep as once believed.
