Does snoring cause ADHD?
A new study of more than 11,000 children in the UK shows a link between early “sleep-disordered breathing” and behavioral problems like hyperactivity and aggression. In the survey, published in the March 5th Pediatrics, researchers from Albert Einstein School of Medicine in New York looked at data from the Avon Longitudinal Study of Parents and Children. Over the course of 6 years parents reported on their children’s snoring, mouth breathing, and sleep apnea about once a year starting when the child was 6 months. They also assessed the child’s behavior at age 4 and 7.
• Children whose sleep-disordered breathing (SDB) peaked at 6 or 18 months old were between 40 and 100 percent more likely to develop behavioral problems by age 7, compared to youngsters who sleep alright.
• Kids who had the worst SDB early on were 1.5 times more likely to be hyperactive.
• Those with the most sleep disturbances also showed emotional and conduct problems (i.e. trouble with friends, aggressive behavior).
• Children with the worst behavioral problems showed breathing disturbances throughout infancy (their bad sleep peaked at 30 months).
Okay, a pretty good set of data. First off it’s very large. Also it’s collected over time with the predictor (bad breathing at night) evaluated before the onset of the outcome variables (attention, conduct, friend trouble, etc.) plus a variety of confounding factors that might explain why kids who snore and such might act up - prematurity, family stress, mom’s schooling, dad’s employment situation.
Self-Report Survey. All the data comes straight from the parents who filled out the questionnaires. Not awful but would have been better if there’d been someone else, a professional perhaps, doing an evaluation or two. Maybe a teacher’s opinion.
Other Explanations?Time Lag? Yes the researchers controlled for 15 variables but it’s still quite possible other factors entered into the equation. The bad sleep peaked in infancy and early toddlerdom and yet we’re blaming it for behavior some 2 to 6 years later. So there was plenty of time between 6 months and age 4 let alone 7 for these other factors to come into play, factors that might both explain the disrupted sleep and disruptive behavior. It was more common to find kids who were premature, had moms who smoked during pregnancy and were in lower socioeconomic households among the poor rather than normal sleepers. Curious because it suggests there might be other reasons for the poor sleep and later issues.
How does bad sleep supposedly fuel hyperactivity, aggression, poor emotional regulation and peer relations? The theory goes that snoring and other night-time breathing complications deplete oxygen in the brain and messes with the so-called restorative powers of sleep and thus, don’t panic, impair brain development.
Apparently 1 in 10 kids frequently snores and 2 to 4% stop breathing momentarily (sleep apnea) according to the American Academy of Otolaryngology "Health and Neck Surgery" (AAO-HNS). Much of the disordered breathing comes from oversized tonsils or adenoids.
Tenuous Link to ADHD. The snoring-depletes-oxygen theory cannot possibly explain all ADHD or even all kids misdiagnosed with it. This survey didn’t assess ADHD at all. Even if bad sleep contributes to a small percentage of actual ADHD cases (in so much as the depleted oxygen creates abnormal brain function contributing to ADHD) then that’s still a lot kids with some 5 to 6 million diagnoses in the US.
Of course some kids who don’t get a good night’s rest may just be tired and not brain-damaged. Once the sleep issue gets fixed (i.e. tonsils out, adenoids out) the ADHD-like tendencies might vanish. In fact that possibly is being tested in a study underway by Dr. Ronald Chervin, a University of Michigan neurologist and sleep expert who also co-authored the current study.
The relationship between ADHD and sleep? It’s complicated. The academic literature is teeming with studies and findings. Kids with ADHD struggle with sleep, some due to meds, some just because. Lack of sleep exacerbates symptoms. Sleep deprivation mimics the symptoms in those without the disorder. The findings go on and on.
Anyhow, the average kid has always been sleep-deprived according to experts who’ve been saying so for over 100 years. If you can’t nod off yourself (or would like to) read this review of sleep recommendations published online in the February 13th Pediatrics: Never Enough Sleep: A Brief History of Sleep Recommendations for Children.
In the Media:
Children with Abnormal Breathing In Sleep - Show Tendency For Behavioral Problems
in Medical News Today
Do Snoring Babies Become Troubled Children?
in Healthland, Time
Snoring, Mouth-breathing Tots More Likely to Develop Behavioral Problems
in CBS News
Bonuck, Freeman, Chervin and Linzhi. (2012). Sleep-Disordered Breathing in a Population-Based Cohort: Behavioral Outcomes at 4 and 7 Years. Pediatrics, March 5th. doi: 10.1542/peds.2011-1402