How Early Can Autism Be Detected?

Autism symptoms were not detectable at 6 months age but began to show up by one year

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Early help for kids with autism spectrum disorders (ASD) can be important. But how young can we detect the early symptoms of ASD? A recent study tracked kids for the first three years of life.

These researchers found that they couldn’t tell the difference between the kids without ASD and those that later developed ASD at 6 months old.

By 14 months, the kids with ASD started to show differences in social, language and motor skills.

"Ask a pediatrician about autism risk."

Researchers, led by Rebecca J. Landa, PhD, of the Kennedy Krieger Institute and the Johns Hopkins University School of Medicine, followed kids over the first three years of life to track their development. 

They followed 235 kids, some of which had a sibling with autism and were considered at high risk of developing ASD.

The researchers wanted to see when behavior started to look different for kids who later developed ASD.

They tested at the kids at 6, 14, 18, 24, 30 and 36 months of age. They used play-based tests to measure motor skills, play skills, language skills and sharing of emotion.

At 3 years old, all the children were assessed clinically for ASD to confirm diagnoses suspected at scheduled visits.

They split the children into three groups after diagnosis: 1) those that didn’t develop ASD, 2) those that developed ASD by 14 months and 3) those that were diagnosed with ASD after 14 months of age.

They found that all kids fared about the same on the tests at 6 months old. They were unable to detect who would go on to develop ASD.

However, by 14 months, the kids who developed ASD began to differ from kids who never developed ASD.

At the 14 month visit, the kids that were given a diagnosis of probable ASD showed deficits in most of the skills measured compared to the non-ASD group.

The group that was diagnosed at a later age also began showing deficits in language and motor skills at the 14 month visit compared to kids who never developed ASD.

The authors concluded that there is a lower age limit under which autism cannot be detected. At 6 months old, children with and without ASD are developing in similar ways.

By 14 months, the development of kids with autism is beginning to differ from typically developing children.

This study was published October 30 in Child Development.

The authors report no conflicts of interest. The study was funded by the National Institutes of Health and Autism Speaks.

Reviewed by: 
Review Date: 
October 29, 2012
Last Updated:
November 1, 2012