Associations Between Comorbidities, Developmental Status, and Disease Severity in Children With Autism Spectrum Disorder: A Multicenter Cross-Sectional Study in China.

Every child was recruited from a hospital clinic, mostly tertiary centres, so children with milder or less complex autism are likely to be under-represented. 89.2% of the children were under 6, and the 138 aged 6 or over were too few for reliable subgroup results, so the age differences should not be read as how comorbidity develops over childhood. It is a single snapshot. It can show which conditions cluster together but not whether a comorbidity worsens autism symptoms, or the reverse. Missing data reached 20.4% for some variables and were filled in statistically; the authors report that complete-case and imputed results differed somewhat, although the main associations held. Developmental level was missing for many children and was filled in statistically, so the intellectual disability figures rest partly on estimated scores. Only 250 children had Wechsler testing. Children with uncontrolled seizures or unstable conditions were excluded, so the findings do not cover the full range of children with autism. Anxiety, depression and ADHD were assessed only in small subgroups, so their prevalence in this cohort is unknown. The 87.3% rate of intellectual or developmental disability is far above Western reports of 21.7% to 33%; the authors attribute this to referral patterns and late diagnosis, and it may not reflect children seen in the community.

Funded by government and charitable research grants in China and Sweden: the National Natural Science Foundation of China, the Henan Medical Science Foundation, the Henan Science and Technology Foundation, the Swedish Research Council, the Adlerbert Research Foundation, Stiftelsen Edit Jacobsons Donationsfond, and the Joint Open Research Fund of Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center. No company that sells a treatment is named among the funders, and the authors declare no conflicts of interest. The study involved no therapeutic intervention.

Do not read these links as cause and effect. The study is a single snapshot, so it cannot show whether insomnia, food refusal or intellectual disability make autism symptoms worse, or whether more severe autism leads to these conditions. It also cannot show that treating a comorbidity such as insomnia or constipation will improve autism severity. And because the children came from hospital clinics and 89.2% were under 6, the 87.3% intellectual or developmental disability figure should not be read as the rate among autistic children generally.