Systematic Intervention for Children with Autism Spectrum Disorder and Integration in Regular School Classes: A Naturalistic Study

Kotsopoulos and her team tracked 32 preschoolers with autism through three years of community ABA. The kids got 25 to 30 hours a week of one-to-one teaching at a local clinic. After that, the staff helped each child move into a regular public-school class.

The study had no control group. The team simply watched the same kids over time and scored them before and after.

Every child looked better on the CARS and Vineland scales. Thirteen of the 32 no longer met the ADOS-2 cut-off for autism. Most parents reported that their child kept up in a typical grade without major behavior problems years later.

Fernell et al. (2011) saw a similar win: 31% of toddlers exited their inclusive ABA program in the typical range after only eight months. Kotsopoulos stretches that idea to three years and shows the gains can last into elementary school.

Yet Fernell et al. (2011) also clash with the Swedish study by Fernell et al. (2011). That paper found almost no extra benefit from high-intensity ABA when many kids had low IQ. The difference is the kids: the Swedish sample had more intellectual disability, while Kotsopoulos’ group appears higher-functioning. Same treatment, different starting point.

Grindle et al. (2012) and Pitts et al. (2019) push the model forward. They moved ABA out of the clinic and into real school rooms. Both showed solid adaptive gains, proving the approach works inside mainstream or special-ed buildings, not just at a center.

You now have evidence that three years of early, community-based ABA can clear the path to regular school. When you write treatment plans, aim for the 25–30 hour range and plan hand-off meetings with teachers early. Track CARS and Vineland each year; if scores stall, check for cognitive or medical issues before assuming the program has failed.