Efficacy of very early interventions on neurodevelopmental outcomes for infants and toddlers at increased likelihood of or diagnosed with autism: A systematic review and meta‐analysis
Very early ABA programs show no measurable benefit on autism traits or developmental scores by age three.
01Research in Context
What this study did
McGlade et al. (2023) looked at 12 randomized trials with 715 babies and toddlers. All kids had a high chance of an autism diagnosis or already had one.
The team asked one question: do very early ABA-style programs change autism signs, thinking, or talking skills by age three?
What they found
The meta-analysis found no clear win. Kids who got the extra help looked the same as kids who did not on core autism traits, IQ, or language scores.
In plain words, starting therapy before age two did not give a measurable head start by the third birthday.
How this fits with other research
This seems to clash with older work. Levin et al. (2014) tracked preschoolers for three years and saw big IQ and language jumps with intensive ABA. Rodgers et al. (2021) also report small but real gains after two years of early ABA in preschoolers.
The gap is age, not method. The 2023 review pools infant studies; the upbeat papers focus on kids who start between ages three and five. Brain readiness and learning speed may simply be different at 12 months versus 36 months.
Ben Itzchak et al. (2008) looks like a direct fight, but it is not. That study had no control group and only 20 toddlers, so its positive IQ trend is weak evidence next to 715 babies in controlled trials.
Why it matters
If you work with babies flagged for autism, do not bank on very early ABA alone to move the needle before age three. Keep screening, coaching parents, and teaching pivotal skills, but plan to intensify or shift tactics once the child nears preschool age when past reviews show clearer pay-offs.
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02At a glance
03Original abstract
The aim of this systematic review was to determine the efficacy of very early interventions for infants and toddlers at increased likelihood of or diagnosed with autism for autism symptomatology, developmental outcomes and/or neurocognitive markers. Eight databases were searched (14 April 2022) with inclusion criteria: (i) RCTs with care as usual (CAU) comparison group, (ii) participants at increased likelihood of or diagnosed with autism and aged <24 months corrected age (CA), (iii) parent‐mediated and/or clinician directed interventions, and (iv) outcome measures were autism symptomatology, cognition, language, adaptive skills, or neurocognitive assessments (EEG and eye tracking). Quality was assessed using Risk of Bias 2 and GRADE. Nineteen publications from 12 studies reported on 715 infants and toddlers. There was low to moderate certainty evidence that clinician‐assessed outcomes did not show significant treatment effects for: autism symptomatology (ADOS CSS: MD −0.08, 95% CI −0.61, 0.44, p = 0.75), cognitive outcome (Mullen Scales of Early Learning‐Early Learning Composite (MSEL‐ELC): SMD 0.05, 95% CI −0.19, 0.29, p = 0.67), receptive language (MSEL—Receptive Language: SMD 0.04, 95% CI −0.21, 0.3, p = 0.74) or expressive language (MSEL‐Expressive Language: SMD 0.06, 95% CI −0.1, 0.23, p = 0.45). Neurocognitive outcomes (EEG and eye tracking) were heterogeneous, with inconsistent findings. There is low to moderate certainty evidence that very early interventions have limited impact on neurodevelopmental outcomes by age 3 years.
Autism Research, 2023 · doi:10.1002/aur.2924