Sleep Apnea and IQ: What Studies Show in Children and Adults

Does sleep apnea lower IQ? The evidence is weaker than the headlines. In children, sleep-disordered breathing goes with IQ scores a few points lower in several studies, but the largest recent cohort, 11,875 children followed for five years, found snoring unrelated to every cognition score it measured, and no treatment trial has shown an IQ gain. In adults, the best-known meta-analysis found a negligible effect on intellectual functioning and a substantial one on vigilance and executive function. The fair summary is an association in some studies, a cause that is unproven, and attention, behaviour and memory affected more reliably than IQ.

What is sleep apnea, and how common is it?

Obstructive sleep apnea is repeated narrowing or collapse of the airway during sleep. In adults the American Academy of Sleep Medicine bands severity by breathing events per hour: mild is 5 to under 15, moderate 15 to 30 and severe over 30. A 2019 modelling study in The Lancet Respiratory Medicine, funded by the CPAP maker ResMed, estimated that 936 million adults aged 30 to 69 have mild to severe apnea and 425 million moderate to severe. In the United States, a 2013 estimate from a Wisconsin cohort of 1,520 people put moderate to severe apnea at 10% of men aged 30 to 49 and 17% of men aged 50 to 70, against 3% and 9% of women. These are modelled figures, not head counts. In children, the American Academy of Pediatrics technical report found the prevalence of the syndrome ranging from 0% to 5.7% across studies, and a 2025 paper from the ABCD cohort says one in ten children has some sleep-disordered breathing, a broader group that includes snoring.

Does sleep apnea lower IQ in children?

Several studies find a gap, usually of a few points. They are observational, so they show a link, not a cause:

• Gottlieb and colleagues, 2004, Journal of Pediatrics, 205 five-year-olds, 61 with parent-reported breathing symptoms: full-scale IQ 105.9 against 111.7 (p = .02), a gap of 5.8 points. The gap persisted when children with sleep-study-confirmed apnea were left out, and there was no difference on a computerised attention task
• Hunter and colleagues, 2016, American Journal of Respiratory and Critical Care Medicine, 1,010 children aged 5 to 7 with overnight sleep studies: a general ability score of 102.1 in non-snorers, 99.7 in habitual snorers with normal sleep studies, 98.8 at 1 to 5 breathing events an hour and 93.9 above 5 an hour (141 children), an 8.1-point gap. The children with the most events also had a higher body-mass index
• Kennedy and colleagues, 2004, 13 snorers and 13 non-snorers: global IQ 96.7 against 110.2. With 26 children the estimate is very rough
• Halbower and colleagues, 2006, PLoS Medicine, 19 children with severe apnea and 12 controls aged 6 to 16: significant deficits in full-scale IQ and executive function (we could not read the IQ means)

A 2022 meta-analysis in Sleep Medicine Reviews (Menzies and colleagues, 63 studies pooled) reported that the largest impairments were in intelligence, verbal and overall, and that children with primary snoring were not spared. To put the gaps in context, 5.8 points is 0.39 of a standard deviation on the usual 15-point scale, which would move a child from the 50th percentile to the 35th, and 8.1 points is 0.54 of a standard deviation, to the 29th (our arithmetic; our IQ percentile calculator converts any score). A gap of that size is real for a group, but it is a group average, not a prediction for any one child.

The link is not simple, though. A 2012 study of 153 children aged 3 to 5 (Jackman and colleagues) found sleep-disordered breathing of any severity associated with poorer behaviour but not cognitive performance. And the largest recent cohort, the ABCD study (Isaiah and colleagues, JAMA Network Open, 2024), followed 11,875 children and found that snoring was not associated with any of the NIH Toolbox scores, only with problem behaviour. The Toolbox is not an IQ test, and snoring is a milder marker than diagnosed apnea, but the result cuts against the headline that snoring lowers IQ. Our look at screen time and cognitive test scores in children shows how often a childhood exposure links to small score differences that large cohorts then fail to confirm.

Does treating sleep apnea raise a child's IQ?

Not in any trial we found. Adenotonsillectomy, the removal of the tonsils and adenoids, is the first-line treatment, and three randomised trials tested what it does:

• CHAT (New England Journal of Medicine, 2013), 464 children aged 5 to 9, early surgery against watchful waiting: the attention and executive-function score improved by 7.1 points with surgery and 5.1 without, a difference that was not significant (p = 0.16), while sleep studies normalised in 79% of operated children against 46%. A 2016 follow-up in Pediatrics found small gains (d = 0.20 to 0.24) on nonverbal reasoning, fine motor skills and selective attention, and "failed to find any benefit" on language, visual perception or global cognitive ability
• POSTA (Pediatrics, 2020), 190 children aged 3 to 5 with mild apnea, the only trial we found with IQ as its primary outcome: no cognitive gain on the Woodcock-Johnson III Brief Intellectual Ability at 12 months, although sleep arousals, apnea indices and parent-reported symptoms improved
• PATS (JAMA, 2023), 459 children aged 3 to 12.9 with snoring and mild or no apnea: surgery did not significantly improve executive function or attention at 12 months, but behaviour, symptoms, quality of life and blood pressure improved

A 2026 pooled analysis of eight studies (Lee and colleagues, searched to August 2025) fits the pattern: surgery produced a moderate improvement in parent-reported behaviour (standardised difference -0.58) and a smaller one in executive function (-0.25), and objective neurocognitive measures were not significant. In a non-randomised comparison, Biggs and colleagues (2014) found that improvement in apnea scores predicted improvement in performance IQ, not verbal IQ, among 12 treated children set against 26 untreated, which is suggestive but small.

What does sleep apnea do to thinking in adults?

In adults the picture shifts from IQ to attention. Beebe and colleagues' 2003 meta-analysis in Sleep, pooling 25 studies with 1,092 adults with untreated apnea and 899 controls, found a negligible impact on intellectual and verbal functioning but a substantial one on vigilance and executive functioning. Memory is affected too: Wallace and Bucks (2013) pooled 42 studies, 2,294 adults with untreated apnea and 1,364 controls, and found impaired verbal episodic memory (immediate recall, delayed recall, learning and recognition) but not visual immediate recall or visuospatial learning. A later meta-analysis of 19 studies (Stranks and colleagues, 2016) reported negative effects in more domains, including verbal reasoning, so the verbal question is not closed. We found no study whose headline result was a Wechsler full-scale IQ comparison of adults with apnea and healthy controls.

Treatment trials in adults are modest. The APPLES trial (Kushida and colleagues, 2012; 1,098 participants, six months, sham-controlled) found that CPAP gave a mild, transient improvement in the most sensitive measures of executive and frontal-lobe function for people with severe disease. A 2024 pooled analysis of 11 randomised trials (923 patients) found improvement on one executive test, the Trail Making Test part B, and no global effects on other cognitive domains.

The dementia link is stronger but observational. Yaffe and colleagues (JAMA, 2011) followed 298 women with a mean age of 82 and found that 44.8% of those with sleep-disordered breathing developed mild cognitive impairment or dementia against 31.1% of those without (adjusted odds ratio 1.85, 95% confidence interval 1.11 to 3.08). A 2026 study in the Alzheimer's Association journal, by Kaufmann and colleagues, of 777 Medicare beneficiaries with an apnea claim reported that untreated participants declined 69% faster than CPAP users. In absolute terms CPAP users declined by 0.03 standard deviations a year and untreated participants by roughly 0.05 (our arithmetic), CPAP use was identified from billing claims, and the outcome was a composite cognitive score, not IQ. Our guides to hearing loss and cognitive test scores and to whether an IQ test can detect dementia cover the same kind of late-life link.

How should you read a claim that sleep apnea lowers IQ?

• Check what was measured: an IQ test, a computerised attention task, parent-rated behaviour or an executive-function questionnaire. Many headline effects are on the last two
• Check the design: cohort and case-control studies show links, and only randomised trials test whether treatment changes scores. None of the trials above found an IQ gain
• Check the confounders: in Hunter's study the children with the most breathing events also had a higher body-mass index, and children who snore differ from those who do not in other ways
• Check the size: a gap of 6 to 8 points is about a third to a half of a standard deviation, a group average rather than a forecast for one child
• Check the sample: the smallest studies here have 26 or 31 children, and a single score always carries a margin, as our note on the IQ margin of error explains

The short answer is that sleep apnea has not been shown to lower IQ. In children it goes with a few points less in some studies and with none in the biggest cohort, treatment trials show gains in sleep and behaviour rather than IQ, and in adults the strongest effects are on attention, executive function and memory. If sleep is your question, our guides to sleep and IQ and to what sleep loss does to test performance cover the wider evidence, executive function versus IQ explains why the two are measured differently, and the IQ Metrics test gives a measured score of your own.

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