Many autistic people also live with other conditions — intellectual disability, sleep problems, mental health conditions and more. This page explains surveillance findings and NIH-funded studies, including one that cleared a widely discussed pregnancy exposure.
Based on CDC MMWR Surveillance Summaries · NIH media advisory · NIH · NIMH · All sources · Checked November 3, 2026
39.6%of 8-year-olds with autism and cognitive data were classified as having an intellectual disabilityCDC ADDM · MMWR April 17, 2025
2 million+Swedish children in the sibling study finding no causal acetaminophen linkNIH · April 11, 2024
432children in the NIH-funded infant sleep study — a small, non-causal studyNIH · May 7, 2020
Orientation: autism rarely travels alone
Surveillance and NIH-funded studies describe conditions that often occur alongside autism — intellectual disability, sleep difficulties, and mental health conditions among them — and test claims about exposures during pregnancy. NIH’s 2022 Autism Centers of Excellence include a Stanford center studying sleep in autism and a University of Pittsburgh project on mental health in autistic adults; those are funded studies, not yet findings.
April 17, 2025 · MMWR Surveillance Summaries (CDC) · Surveillance report, 2022 data
About 4 in 10 eight-year-olds with autism and available cognitive data were classified as having an intellectual disability
What they studied: As part of its 2022 surveillance across 16 sites, CDC’s ADDM Network recorded cognitive test results where available for 8-year-olds identified with autism.
What they found: Among children with cognitive data, 39.6% were classified as having an intellectual disability (an IQ of 70 or lower, or an examiner’s statement). Cognitive data were available for 61.4% of these children.
Why it matters / limits: CDC notes that the intellectual-disability measure is a surveillance definition rather than a clinical diagnosis, that IQ scores in young children may be unstable, and that the surveillance areas are not nationally representative. The figure describes records in monitored communities, not any individual child.
Read the original source April 11, 2024 · NIH media advisory · JAMA · Sibling-comparison register study
No causal link between acetaminophen in pregnancy and autism, ADHD or intellectual disability
What they studied: NINDS-funded Swedish and American researchers analysed data from more than 2 million children in Sweden, using the Swedish Medical Birth Register and Prescribed Drug Register, and compared siblings — who share genetics, parental health and many other factors.
What they found: Before siblings were considered there appeared to be a small increase in risk, as earlier studies had reported. In the sibling comparison, acetaminophen exposure during pregnancy was not linked to autism, ADHD or intellectual disability; NIH says the earlier connection “is likely due to other underlying factors”, such as the reasons a person takes the medicine.
Why it matters / limits: NIH names a limitation: the data rely on prescribed acetaminophen and self-report during prenatal care, so over-the-counter use and dosage may not be fully captured. Decisions about any medicine in pregnancy belong with your own provider.
Read the original source May 7, 2020 · NIH news release · The American Journal of Psychiatry · Longitudinal infant study
Early sleep problems in infants with an autistic sibling were linked to a later diagnosis — in a small study
What they studied: In the NIH Autism Centers of Excellence Infant Brain Imaging Study Network, parents of 432 children answered sleep questions at 6 and 12 months, children had MRI scans at those ages, and were assessed for autism at 24 months. Of the children, 305 had a sibling previously diagnosed with autism; 71 of those met criteria for autism at 24 months, while none of the 127 children without an autistic sibling did.
What they found: High-risk children who met criteria for autism scored higher for sleep problems at 6 and 12 months than the other groups, and showed more growth in the hippocampus from 6 to 24 months than high-risk children without sleep problems.
Why it matters / limits: NIH calls the result “a promising lead” and the study small. It did not look for cause and effect, could not measure overall sleep quality, and the authors called for studies with more comprehensive sleep measures. Sleep concerns at any age are worth raising with your child’s provider regardless.
Research explained here is educational. A single study — however large or well designed — does not change clinical care on its own; findings need to be repeated by other teams before they shape guidelines. Surveillance figures describe the communities that were monitored, not a national count, and they do not show causes. Laboratory models are not tests or treatments. Funding announcements describe what will be studied, not what has been found. If something here raises a question about your child or yourself, take it to your health care provider or care team.
Co-occurring conditions are diagnosed and managed individually by a care team; the studies above describe patterns in groups, not what any one person will experience. Questions to ask after a diagnosis.
This website provides general educational information. It does not diagnose autism or replace individualized medical, developmental, psychological, or educational advice. Screening is not diagnosis.
External listings do not imply affiliation, endorsement, or guaranteed services. Eligibility, availability, costs, and insurance coverage may change. Research summaries reflect evidence available at the time of review.
