Autism & Developmental

Outcome of young children with autism: does the amount of intervention influence developmental trajectories?

Darrou et al. (2010) · Autism : the international journal of research and practice 2010
★ The Verdict

More therapy hours did not speed development—quality targets beat quantity.

✓ Read this if BCBAs writing preschool autism treatment plans
✗ Skip if Clinicians serving only school-age or non-autistic clients

01Research in Context

01

What this study did

The team watched young children with autism for three years. They counted how many therapy hours each child got each week.

They tracked changes in autism symptoms, talking skills, and daily living skills. Then they asked: did kids who got more hours improve faster?

02

What they found

Kids got better. Their autism signs softened and their words and play grew. Yet the number of weekly hours made no difference.

A child with 15 hours a week gained just as much as a child with 35 hours.

03

How this fits with other research

Fernell et al. (2011) ran the same test in Sweden with 208 preschoolers. They also saw that intensive ABA and lighter ABA produced equal Vineland gains.

Hu et al. (2024) looked deeper. They found hours only mattered for kids who lost skills after age one and who started before four. That slice is smaller than the whole group Céline studied.

Waizbard-Bartov et al. (2022) followed kids to age eleven. Half changed paths after preschool, showing that a child’s trajectory can shift even when hours stay flat.

04

Why it matters

Stop chasing a magic hour count. Use your time to build strong communication and social routines instead. Watch the child, not the clock, and be ready to change goals as the child grows.

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02At a glance

Intervention
not applicable
Design
pre post no control
Sample size
208
Population
autism spectrum disorder
Finding
positive

03Original abstract

The study aims were to identify developmental trajectories of young children with autism and investigate their prognostic factors. The participants were 208 children, assessed first at the age of 5 years, followed longitudinally, and reassessed 3 years later. The children's clinical characteristics and the interventions received were recorded. The results indicated two distinct outcome groups with more stability than change. When changes did occur, they pertained to symptom severity (which decreased) and speech level and adaptive behavior (which improved). A logistic regression analysis pointed out two main risk factors (symptom severity and speech level) and two main protection factors (communication skills and person-related cognition). Surprisingly, the amount of intervention (in terms of number of hours) was not related to outcome.

Autism : the international journal of research and practice, 2010 · doi:10.1177/1362361310374156