Onset patterns prior to 36 months in autism spectrum disorders.

The team looked at the toddlers with ASD. They split them into three groups based on how symptoms first showed up.

Group one lost skills they already had. Group two stopped gaining new skills. Group three never lost skills and kept learning.

Doctors tracked each child from first visit until age three. They scored language, play, and social skills every few months.

Kids who lost skills looked almost typical at 12 months. By 36 months they had the most severe autism symptoms.

Kids who plateaued had some early delays but stayed better than the loss group.

Kids with no loss and no plateau had the mildest symptoms at age three.

Tan et al. (2021) pooled 75 studies and found about 30 percent of kids with ASD lose skills. This backs up Sharp et al. (2010) numbers.

Waizbard-Bartov et al. (2022) followed kids to age 11 and showed half changed severity after age three. This extends the target finding that early pattern predicts later outcome.

Solomon et al. (2018) tracked IQ from age two to eight. Some kids with regression gained 30 points while others lost ground. This shows the same start can lead to very different paths.

Son et al. (2013) found girls with ASD show more regression than boys. This adds a sex lens to the target findings.

If a child loses words or play skills at 18-24 months, act fast. Start full assessment within weeks, not months. Push for intensive services even if the child seemed fine last month. Track progress monthly and adjust plans as needed.