At what age does ASD begin?

Autism spectrum disorder (ASD) reflects differences in how the brain develops and processes information, beginning very early in life. You may not notice anything unusual in a newborn, but subtle signs can sometimes appear before a child’s first birthday — such as less frequent eye contact or not responding to their name. 

By around 12 months, missed milestones like not pointing to show something or not waving goodbye may also become noticeable.

For many children, signs of autism become clearer during the first two years. While it can be difficult to diagnose before 12 months, an experienced professional can often make a reliable diagnosis by around age 2, and in some cases even earlier. 

The 18–24 month stage is also when some children seem to “regress,” meaning they stop gaining new words or skills, or lose abilities they previously had — although this does not happen to every child.

Many children are still not identified until preschool or later; studies show the average age of diagnosis is around 5. For those with more subtle signs, autism may not be recognized until school, adolescence, or even adulthood, when social and academic demands increase. 

Whenever the journey begins, learning about your child’s unique profile is an important step — it helps you build on their strengths and connect them with the support that will help them thrive.