from UCL have found that children with irregular bedtimes are more likely to
have behavioural difficulties.
which is published in the journal Paediatrics, found that irregular bedtimes
could disrupt natural body rhythms and cause sleep deprivation, undermining
brain maturation and the ability to regulate certain behaviours.
Yvonne Kelly (UCL Epidemiology & Public Health), said: "Not having
fixed bedtimes, accompanied by a constant sense of flux, induces a state of
body and mind akin to jet lag and this matters for healthy development and
know that early child development has profound influences on health and
well-being across the life course. It follows that disruptions to sleep,
especially if they occur at key times in development, could have important
lifelong impacts on health."
data from more than 10 000 children in the UK Millennium Cohort Study, the team
collected bedtime data at three, five and seven years, as well as incorporating
reports from the children's mothers and teachers on behavioural problems.
A clear link
found a clear clinical and statistically significant link between bedtimes and behaviour
as irregular bedtimes affected children's behaviour by disrupting circadian
rhythms, leading to sleep deprivation that affects the developing brain.
progressed through early childhood without a regular bedtime, their behavioural
scores – which included hyperactivity, conduct problems, problems with peers
and emotional difficulties – worsened. However, children who switched to a more
regular bedtime had clear improvements in their behaviour.
said: "What we've shown is that these effects build up incrementally over
childhood, so that children who always had irregular bedtimes were worse off
than those children who did have a regular bedtime at one or two of the ages
when they were surveyed.
our findings suggest the effects are reversible," continued Professor
Kelly. "For example, children who change from not having to having regular
bedtimes show improvements in their behaviour."
Inconsistent bedtimes reversible
bedtimes were most common at the age of three, when around one in five children
went to bed at varying times. However, by the age of seven, more than half the
children went to bed regularly between 7.30 and 8.30 pm. Children whose
bedtimes were irregular or who went to bed after 9 pm came from more socially
disadvantaged backgrounds, and this was factored into the study findings.
Kelly said: "As it appears the effects of inconsistent bedtimes are
reversible, one way to try and prevent this would be for health care providers
to check for sleep disruptions as part of routine health care visits. Given the
importance of early childhood development on subsequent health, there may be
knock-on effects across the life course. Therefore, there are clear
opportunities for interventions aimed at supporting family routines that could
have important lifelong impacts."