A very important study of children’s sleep has just been published in the journal Pediatrics. It is the first prospective longitudinal study of associations between serious sleep problems in very young children and their later need for special education services. It has long been known that children with numerous kinds of disabilities have a disproportionate number of sleep problems compared with typically developing children. For example, a high percentage of children with Down Syndrome have sleep problems of some kind, with estimates ranging from 50 to 70 percent. Similarly, children with autism, attention deficit hyperactivity disorder (ADHD) and other intellectual disabilities have high levels of these problems.
In a forthcoming article that will appear in the journal Exceptional Children, I review many of these studies and discuss possible underlying mechanisms. But the majority of these studies have looked at sleep and disability co-occurrence in children long after the symptoms of either have emerged. Such studies may suggest, but not prove, that one condition has a causal effect on the other. Sleep problems could contribute to learning problems, or it could be that the disability causes sleep problems. Also, both of these may be the case in a relation that is called bidirectional, with each contributing to the manifestation of the other. Further, both sleep and disability may be influenced by a third set of factors, such as genetic or epigenetic factors. But the study in Pediatrics is different and breaks new ground in understanding how these problems develop over time by providing what is called a prospective population based longitudinal study.
For obvious ethical reasons, children cannot be deliberately exposed to a risk factor to see what the long-term effect is. The best alternative is to conduct a prospective study, meaning that the risk factors and the eventual outcomes are allowed to emerge “naturally” over time. Population based refers to the fact that the sample was taken from the population at large rather than from children who have been referred for clinical services due to a suspected problem. And longitudinal merely means they are followed over a long period of time to determine if early conditions and problems are related to ones that only emerge much later. The authors studied a very large sample of children who were actually recruited before their births. Enrolling 85 percent of pregnant women in a specific section of Southwest England resulted in an initial study group of over 13,000 infants. Infants with serious congenital disorders that could be related to later disabilities were excluded. Thus no infant in the study had any known condition that would lead anyone to suspect a disability later in childhood. Parents reported on snoring, mouth-breathing, and sleep apnea when their children were 6, 18, 30, 42, And 57 months old.
In addition, parents were asked about difficulties relating to sleep that are not uncommon among young children, such as refusal to go to bed, difficulty going to sleep, nighttime awakenings, and nightmares. At age eight, around 16 percent of children had been identified as needing special education services, but children with higher rates of sleep problems had 56 percent increased odds of needing services. This result was found even after controlling for numerous other factors that are often associated with needing special education such as maternal smoking or alcohol during pregnancy, prematurity, or socioeconomic disadvantage.
One important implication is that effective interventions are available for sleep problems in early childhood. For children with serious sleep problems, the treatments include oral appliances, adenotonsillectomy, pharmaceuticals, and training parents to manage sleep-related behaviors. The authors conclude that “Future research should focus on timely and systematic screening and on testing potential interventions…among children at risk for developmental delay/disability.” (p.7).
Bonuck, K., Rao, T., & Xu, L. (2012). Pediatric sleep disorders and special educational need at 8 years: A population-based cohort study. Pediatrics, Volume 130, Number 4, October 2012. www.pediatrics.org/cgi/doi/10.1542/peds.2012-0392
Buckhalt, J. A. (in press). Sleep and cognitive functioning in children with disabilities. Exceptional Children.