Outcome for children with autism who began intensive behavioral treatment between ages 4 and 7: a comparison controlled study.

Eikeseth et al. (2007) compared two groups of children with autism.

One group got intensive one-to-one ABA starting between ages 4 and 7.

The other group got mixed eclectic services in special-ed classes.

Both groups were tracked into elementary school.

The late-start ABA kids gained more IQ points and daily-living skills.

They also had fewer behavior and social problems at follow-up.

Starting ABA at age 5½ still beat the mixed program.

Aznar et al. (2005) looked at 3- to 5-year-olds and saw the same ABA win.

That study is the younger twin of this one; together they show the benefit holds across preschool ages.

Linstead et al. (2017) later crunched a big file and found more hours each week and more months of ABA speed mastery in every skill area.

So Svein’s finding fits: intensity matters even when you start a little later.

Green et al. (2002) pushed the start age down to 12 months and saw normal scores by kindergarten.

That case looks like it clashes with Svein, but the designs differ.

Gina followed one toddler with super-early treatment; Svein compared groups who began years later.

Both agree earlier is better, yet Svein shows you still get real gains if you miss the toddler window.

You can tell families that starting ABA at 4, 5, or 6 is not too late.

Push for high weekly hours and keep the program running.

Kids who begin later can still outscore peers in mixed classrooms on IQ, daily skills, and problem behavior.