Early diagnosis of autism in the community is associated with marked improvement in social symptoms within 1-2 years.
Nitzan Gabbay-Dizdar, Michal Ilan, Gal Meiri and 7 others
PMID 34623179WHAT IT FOUND
Children diagnosed with autism before 2.5 years showed much larger improvements in social symptoms within 1-2 years than those diagnosed later.
This held true even though both groups received similar amounts of community treatment. Earlier diagnosis appears linked to better social outcomes.
Key findings
01Children diagnosed before 2.5 years were significantly more likely to show improvement in social symptoms (65%) compared to those diagnosed later (23%).
02The improvement in social symptoms was significantly larger in the younger group, while restricted and repetitive behaviors actually deteriorated more in this group.
03These differences in social symptom improvement remained significant even after accounting for initial severity, cognitive scores, sex, and time between assessments.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
The study only used ADOS-2 scores to measure outcome, which is a brief clinical observation. It did not include parent or teacher reports, nor did it measure changes in language, adaptive behavior, or cognitive abilities over time. Only about 40% of the children invited for follow-up actually completed it, which could introduce bias if the families who returned were different from those who did not. The study measured the amount of treatment (hours per week) but not the quality or specific type of intervention, so it cannot rule out that younger children received more effective or targeted therapies despite similar hours. The children in the younger and older groups were assessed using different ADOS-2 modules due to their age and language levels, relying on the accuracy of the calibrated severity scores to make these comparisons valid.
Declared interests
The authors declared no conflicts of interest. The study was funded by a National Autism Knowledge Center grant from the Israeli Ministry of Science and Technology.
The easy way to misread this
Do not conclude that early diagnosis alone causes improvement. The study shows an association, but it did not include a group of children who were diagnosed early but received no intervention, so it cannot separate the effect of earlier access to treatment from natural developmental maturation.