Stability and change among high-functioning children with pervasive developmental disorders: a 2-year outcome study.

Glenn et al. (2003) tracked 46 high-functioning children for two years. Half had autism and half had Asperger syndrome. They used the same autism rating scale at the start and again two years later. No extra therapy was given for the study.

Kids were 5 to 8 years old and all spoke in full sentences. The team wanted to see if symptoms got better, worse, or stayed the same.

After two years, most scores barely moved. The Asperger group kept milder social and communication problems than the autism group. Repetitive behaviors stayed almost flat for both groups.

Only a tiny gap closed: social and communication scores edged one point closer. In plain words, kids looked much the same at the end as they did at the start.

Mhatre et al. (2016) followed 80 Indian children for ten years and saw big gains: 8 out of 10 learned to speak and almost half mastered daily living skills. The difference is time. Two years is too short to see major change; ten years gives more room for growth.

Gizzonio et al. (2015) also found flat scores over one year in preschoolers, backing up the "stay-the-same" pattern. Their study adds that boys and girls move in lock-step, so gender is not a useful splitter when you plan goals.

Together, the papers say: expect stability in the short run, but longer windows can reveal real progress, especially when families stay engaged.

Set realistic expectations with parents. Two-year goals should target small, concrete skills, not broad "autism reduction." Keep the Asperger label in mind when writing social goals; those kids usually start with a slight edge. Most important, don’t quit services if scores look flat after a year—long-haul support is where later gains come from.