Persistent night waking and settling difficulties across the first year: Early precursors of later behavioural problems?

This study examined, in a community sample, if persistent sleep difficulties during infancy are an early precursor of later behavioural difficulties. Sixty-eight mothers completed the Child Behaviour Checklist (CBCL 2/3) when their child was 42 months of age. The CBCL scores were examined in light of sleep data collected at 3, 6, 9 and 12 months of age, and temperament ratings that were completed at 3 and 9 months. Night waking decreased from infancy to age 3 years, whereas difficulties with sleep schedule (initiation and duration) increased over time. Fussy temperament during infancy was associated with higher CBCL scores. As night waking across the first year uniquely predicted only 3% of the behavioural scores at 42 months, it was argued that in low-risk infants, persistent night waking, by itself, is not a precursor of later behavioural problems. However, when persistent night waking was combined with ongoing settling difficulties, children were more likely to score higher on the CBCL compared to children who, as infants, were continuously good sleepers. Given that all the measures were based on maternal reports, it is not clear if the modest association between sleep characteristics during infancy and subsequent behavioural adjustment reflects constitutional, contextual, and/or methodological factors.