Autism spectrum disorder diagnoses in Stockholm preschoolers.
In Stockholm, six out of every thousand children had ASD by age six, and those with intellectual disability were identified earliest.
01Research in Context
What this study did
The team looked at every child born in Stockholm in 2002. They checked school and health records to see who had an autism diagnosis by age six.
They counted how many kids got each ASD subtype. They also noted who had intellectual disability, language disorder, or ADHD alongside autism.
What they found
Six out of every thousand six-year-olds had ASD. Kids with intellectual disability were spotted earlier. Kids with Asperger or atypical autism were found later.
Most children had more than one label. Speech delay, ADHD, and learning problems were common partners.
How this fits with other research
van 't Hof et al. (2021) pooled 40 countries and found the world average diagnosis age is still about five. The Stockholm rate fits inside that global picture.
Davidovitch et al. (2023) followed Swedish kids who got their first ASD label after age six. Many had earlier been called language delayed or ADHD. Together the papers show a gap: some children pass the preschool screen yet still need another look once social demands rise in school.
Kantzer et al. (2018) watched toddlers who first screened positive. Two years later, one in five no longer met ASD criteria, but most kept at least one neuropsychiatric diagnosis. The Stockholm snapshot at age six lines up with that steady picture.
Why it matters
Use the six-year mark as a safety check, not a finish line. If a child has language delay or ADHD but not ASD yet, keep monitoring peer play and restricted behaviors. A brief re-screen in first grade can catch the kids who slid past the preschool radar.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Re-check any first-grader with known language delay or ADHD for overlooked ASD signs during your next observation.
02At a glance
03Original abstract
The aims of this study were to estimate prevalence rates of children with autism spectrum disorder (ASD) diagnoses in a cohort of 6-year-old children with birth year 2002, referred to the Autism Centre for Young Children, serving the whole of Stockholm county and on the basis of the available data discuss clinical aspects of assessment, habilitation and follow-up. Records of 142 of a total of 147 (123 boys and 24 girls) identified children with ASD diagnoses were scrutinised with respect to type of diagnosis, cognitive level, other developmental disorders and medical/neurological disorders. The overall prevalence of such disorders was 6.2/1000 (95% confidence interval 5.2-7.2/1000). The rates of learning disability/mental retardation, developmental delay without a specified cognitive level and normal intelligence constituted about one third, respectively. AS and atypical autism tended to be diagnosed more often at age 5-6 years while AD with learning disability/mental retardation was more often diagnosed at age 3-4 years. The awareness of ASDs has resulted in increasing numbers of children being diagnosed at young ages. We conclude that it is important to take into account these children's broader developmental profiles, need for repeated assessment of cognitive functions and follow-up over time and also the requirement for medical/neurological consideration and work-up.
Research in developmental disabilities, 2010 · doi:10.1016/j.ridd.2010.01.007