Associations between early-life mental health and abnormal sleep duration in midlife: findings from a prospective cohort study in Great Britain

ObjectivesTo quantify the association between the state of mental health in childhood and sleep duration at age 46-48 in the 1970 British Cohort Study (BCS70). DesignBCS70 is a prospective birth cohort study of a population-representative sample. SettingData collection was conducted in participants homes across Great Britain. ParticipantsAll individuals born in one week in April 1970 and resident in the UK are eligible to take part, including those born outside the UK who subsequently immigrated. The study has more than 17,000 participants, of whom 8,581 responded at the last available sweep at age 46-48. Main outcome measuresAverage nightly sleep duration at age 46-48, as assessed by five separate methods: self-report, inference from a sleep diary and three algorithms used to process accelerometry data collected using a thigh-worn activPAL 3 device. ResultsAll seven measures of childhood mental ill-health were positively associated with abnormal self-reported sleep duration. Five were associated with abnormal diary-derived estimates and four were associated with abnormal estimates from an accelerometry-based algorithm. Strengths of associations vary. Adjusting for adult mental health symptoms partially attenuated the associations with self-reported sleep duration but not with the more objective estimates. ConclusionsPoor mental health in childhood is associated with abnormal nightly sleep duration at age 46-48. Post-hoc analyses suggest that this association might not be entirely mediated by poor mental health in adulthood. Future research should attempt to replicate these results in diverse samples and assess whether stronger interventions in early-life mental health might have substantial and long-lasting positive impacts on sleep. SummaryWhat is already known on this topic O_LIThe state of a persons mental health in their early life is associated with a range of adult health outcomes. C_LIO_LIThere exists a bidirectional and multifaceted relationship between the state of a persons mental health and their sleep. C_LIO_LIThe longitudinal association between early-life mental health and sleep in adulthood was not well understood. C_LI What this study adds O_LIOur study demonstrates that early-life mental health is associated with an abnormal average nightly sleep duration at age 46 in this sample. C_LIO_LIAssociations between early-life mental health and abnormal average nightly sleep at age 46 were not fully mediated by adult mental health. C_LI