Co-occurring Down Syndrome and Autism Spectrum Disorder: Cognitive, Adaptive, and Behavioral Characteristics.
Over a third of kids with Down syndrome show autism-like behaviors, but their profile differs from idiopathic ASD—screen carefully.
01Research in Context
What this study did
The team asked parents of children with Down syndrome to fill out autism screeners and behavior checklists.
They wanted to see how many kids with DS also showed autism-like traits, and how those kids differed from DS-only peers.
What they found
About 1 in 3 children with Down syndrome screened positive for ASD features.
These children also had more emotional and behavior problems, but their autism pattern looked different from typical ASD.
How this fits with other research
Ferrari et al. (1991) first showed that autistic kids score far lower on social-adaptive skills than kids with DS. The new survey flips the lens: it finds ASD features inside the DS group, proving the overlap runs both ways.
Žic Ralić et al. (2025) used the same parent-survey method in ASD plus intellectual disability and saw the same dip in social-emotional skills when a second diagnosis is present.
Rosello et al. (2022) reviewed ASD plus ADHD and likewise found compounded impairments. Together these papers build a rule: whenever ASD travels with another diagnosis, expect a bump in behavior and social challenges.
Why it matters
If you work with children who have Down syndrome, add an ASD screener to your intake. A positive flag means you should write goals for social play, emotional regulation, and repetitive behavior even if the child does not meet full ASD criteria.
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02At a glance
03Original abstract
Recent research shows that a significant minority of children with Down's syndrome (DS) also meet diagnostic criteria for an autism spectrum disorder (ASD). The present study investigated what proportion of children aged 6-15 years with a confirmed diagnosis of DS in England and Wales display autistic-type behaviours, and explored the characteristics of this group of children. The Social Communication Questionnaire (SCQ) was used to screen for autism characteristics and the Strengths and Difficulties Questionnaire (SDQ) to explore behavioural difficulties. The proportion of children who met the cut-off score for ASD on the SCQ (total score ≥ 15) was 37.7% (95% CI: 33.4-42.0%); for autism (total score ≥ 22) the proportion was 16.5% (95% CI: 13.2-19.8%). Children who met the cut-off for ASD were significantly more likely to be reported as having emotional symptoms, conduct problems and hyperactivity on the SDQ than children who scored well below cut-off (total score < 10). However, the profile of their autism characteristics on the SCQ was atypical compared with individuals with idiopathic ASD. The pervasiveness of ASD in children with DS in England and Wales is substantially higher than in the general population. These children also experience significantly greater behavioural problems than children with DS only. Early detection of autism characteristics is important for appropriate intervention. However, the unusual profile of autism characteristics in this group may affect the recognition of the disorder and hinder the implementation of appropriate interventions.
Journal of autism and developmental disorders, 2022 · doi:10.1002/aur.1371