Going to bed at different times every night throughout early childhood seems to slow children’s mental abilities, according to a study by University College London.
Given the importance of early childhood development on subsequent health, there may be effects throughout a person’s lifetime, suggest the authors, who looked at whether bedtimes in early childhood were related to brain power in more than 11,000 7-year-olds.
Irregular bedtimes were most common at age 3, when one in five children went to bed at varying times. By age 7, more than half the children went to bed regularly between 7:30 p.m. and 8:30 p.m.
Irregular bedtimes at 3 years of age were associated with lower scores in reading, math and spatial awareness in boys and girls, suggesting that around the age of 3 could be a sensitive period for cognitive development.
Children with irregular bedtimes or who went to bed after 9 p.m. came from more socially disadvantaged backgrounds, the findings showed.
The impact of irregular bedtimes seems to be cumulative. Children who had never had regular bedtimes at ages 3, 5 and 7 had significantly lower reading, math and spatial awareness scores than those who had consistent bedtimes.
The study was published online in July in the Journal of Epidemiology and Community Health.
