Children with autism spectrum disorder (ASD) experience trouble sleeping at a rate of 2-3 times higher than typical children. Could bedtime battles with baby be a precursor to something more serious?
A recent study published in the American Journal of Psychiatry looked at sleep onset problems reported by parents, and the growth of the hippocampus in the brain. The hippocampus plays a vital role in memory as well as emotion and learning.
MRI brain scans of 432 children throughout the US were obtained at approximately 6, 12, and 24 months of age as part of the Infant Brain Imaging Study (IBIS). IBIS is a long term MRI study of infants who are considered at risk for autism because they have a sibling with ASD.
IBIS data revealed high-risk infants with sleep problems who developed ASD were associated with increased growth of the hippocampus during early development. The article in the journal goes on to say that at this time, they don’t know why these changes occur, however, “Overgrowth of some structures, but not others, at different stages of development has been frequently reported in ASD.” Furthermore, the hippocampus seems to be sensitive to poor sleep.
The study also included interviews of parents about whether their child had difficulty falling asleep and falling back to sleep when they awoke during the night.
“We found that infants who develop autism have slightly more trouble falling asleep than infants who do not, but the difference was very subtle and only observable at the group level — averaged scores across over 400 infants,” Kate MacDuffee, a clinical psychologist and postdoctoral research associate at the University of Washington Autism Center, tells Parentology.
The research authors do point out that at this time, they do not know whether sleep issues result in the changes in the growth of the hippocampus or the altered development of the hippocampus cause sleep disturbances. It is also possible they are both being affected by a third variable.
“There are a few important limitations of the study that should be followed up in future research,” MacDuffee says. “First, our measure of sleep problems based on parent report. It will be important to replicate these findings using objective tools for measuring sleep patterns directly, such as actigraphy or polysomnography. My colleague Dr. Estes [senior author on the paper], hopes to collect longitudinal data on sleep difficulties over a longer time span, to learn whether sleep disruptions in infancy persist and lead to the development of full-blown sleep disorders in childhood and whether patterns of brain development continue to look different for children with ASD and sleep problems.”
McDuffee does not think that sleep issues in the first year should be considered a marker for ASD.
“Sleep in the first year of life is incredibly dynamic as infants shift from sleeping most of the day to a more adult-like sleep/wake schedule,” she says. “Ups and downs in this process are typical. However, we also know that healthy sleep is important for children and their families, so we would encourage parents who are worried about their child’s sleep to seek out help from their doctor or other behavioral health providers.”
Trouble Sleeping Autism – Sources
TOP IMAGE: Kiyomi Taguchi/University of Washington
News Medical – Hippocampus Functions
The American Journal of Psychiatry – Sleep Onset Problems and Subcortical Development in Infants Later Diagnosed With Autism Spectrum Disorder