Young children who screen positive for autism: Stability, change and "comorbidity" over two years.
Toddlers who screen positive for autism often keep the diagnosis but swap comorbidities—reassess the whole profile every two years.
01Research in Context
What this study did
Kantzer et al. (2018) followed 96 toddlers who first screened positive for autism. Two years later the team checked who still met full ASD criteria and what other conditions had appeared.
They also looked at whether early cognitive scores or autism subtype better predicted later daily-living skills.
What they found
Seventy-nine of the 96 children still had ASD at follow-up. Most carried at least one extra neurodevelopmental diagnosis such as ADHD, language disorder, or intellectual disability.
Early cognitive level, not autism subtype, forecast later adaptive skills. Labels shifted; learning needs stayed.
How this fits with other research
Morrison et al. (2017) saw the same 2-year window: 73 % kept an ASD label while 64 % dropped co-occurring intellectual disability. Anne-Katrin’s numbers line up, showing the pattern is stable across samples.
Dellapiazza et al. (2024) tracked 575 children for three years and also found half changed severity. Their larger cohort extends Anne-Katrin’s warning that static treatment plans miss real shifts.
Zhang et al. (2026) adds a twist: in Chinese toddlers, ADOS scores for ASD and broader-autism-phenotype overlap through age 3. This supports Anne-Katrin’s call to re-evaluate before locking a diagnosis.
Why it matters
For BCBAs, the message is simple: treat the child in front of you today, not the file from last year. Re-run cognitive and adaptive tests every two years. Update goals when new diagnoses appear. A child who keeps the ASD label may still outgrow severe language or attention issues, so blend interventions instead of stacking them blindly.
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02At a glance
03Original abstract
BACKGROUND: Autism spectrum disorder (ASD) is a developmental disorder with a wide variety of clinical phenotypes and co-occurrences with other neurodevelopmental conditions. Symptoms may change over time. AIMS: The aim of the present study was to prospectively follow 96 children, initially assessed for suspected ASD at an average age of 2.9 years. METHODS AND PROCEDURES: All children had been identified with autistic symptoms in a general population child health screening program, and had been referred to the Child Neuropsychiatry Clinic in Gothenburg, Sweden for further assessment by a multi-professional team at Time 1 (T1). This assessment included a broad neurodevelopmental examination, structured interviews, a cognitive test and evaluations of the child́s adaptive and global functioning. Two years later, at Time 2 (T2), the children and their parents were invited for a follow-up assessment by the same team using the same methods. OUTCOMES AND RESULTS: Of the 96 children, 76 had met and 20 had not met full criteria for ASD at T1. Of the same 96 children, 79 met full ASD criteria at T2. The vast majority of children with ASD also had other neurodevelopmental symptoms or diagnoses. Hyperactivity was observed in 42% of children with ASD at T2, and Intellectual Developmental Disorder in 30%. Borderline Intellectual Functioning was found in 25%, and severe speech and language disorder in 20%. The children who did not meet criteria for ASD at T2 had symptoms of or met criteria for other neurodevelopmental/neuropsychiatric disorders in combination with marked autistic traits. Changes in developmental profiles between T1 and T2 were common in this group of young children with ASD. The main effect of Cognitive level at T1 explained more than twice as much of the variance in Vineland scores as did the ASD subtype; children with IDD had significantly lower scores than children in the BIF and AIF group. Co-existence with other conditions was the rule. CONCLUSIONS AND IMPLICATIONS: Reassessments covering the whole range of these conditions are necessary for an optimized intervention-adapted to the individual child's needs.
Research in developmental disabilities, 2018 · doi:10.1016/j.ridd.2016.10.004