Objectives: There has been limited data on familial aggregation of insomnia. We aimed to explore the prevalence, risk factors and familial aggregation of childhood insomnia with a large community-based sample.
Methods: A community-based epidemiologic study of sleep disorders was conducted among primary school children. Those children with at least one reported biological parent were recruited. A total of 5695 children (mean age 9.2; SD 1.8), 4939 of their reported biological mothers (mean age 38.9; SD 4.6) and 4289 of their reported biological fathers (mean age 43.3; SD 5.5) were studied.
Results: The rates of insomnia 3 times/week in the past 12 months were 4.0%, 12.8% and 9.7% for children, mothers and fathers, respectively. A robust familial aggregation of insomnia was found even after adjustment of the shared environmental and socio-demographic factors. There was a significant dose-response relationship among the children across their parental status from neither, fathers, mothers to both parents with insomnia [3.0%, 7.1%, 9.5% and 11.9%; with ORs (95% CIs)=2.48 (1.82-4.37) for fathers, 3.42 (2.55-4.59) for mothers and 4.42 (2.42-8.10) for both parents, respectively]. In addition, the frequency of insomniac symptoms of the parents also had a dose-response effect on the rate of insomnia of their children.
Conclusions: Insomnia is a common problem in both children and their parents. A significant familial aggregation of childhood onset insomnia was seen in this study even after adjustment of the co-risk factors. There was a dose-response effect of parental insomnia on the rate of insomnia of their children with a slight predilection of maternal influences.