CHICAGO (CBS) — If you feel your preschooler might have autism, follow your gut and get your child tested. A mother, along with an award winning teacher, both say that early intervention makes all the difference.

As CBS 2’s Suzanne Le Mignot reports, when Eva Padilla’s son, Leo, was 18 months old, she felt something just wasn’t right.

“He didn’t play with anything. He was just running in lines,” Padilla said. “No television. No games. No toys. He didn’t have any favorite toy.”

Also, as a mother, one of the hardest things was that “he would never look at me,” she added.

At 18 months, Leo went from saying about seven words to not speaking at all by age 2. Padilla followed her instincts and had her son tested for autism. He was diagnosed with moderate autism.

Asked how critical it is that parents seek early intervention if they suspect their child has autism, teacher Nicole Gorton said, “It’s extremely critical because 25 to 50 percent of children who are getting that intensive early intervention are going to end up in a general education kindergarten class. And that’s our first step in getting them independent for the rest of their life.”

Leo worked with Gorton, a teacher at Ortiz Elementary School and the recipient of the Kohl McCormick Early Childhood Teaching Award.

Now 4 years old, Leo uses the Picture Exchange Communication System – a book with a series of images that helps Leo express what he wants to say.

“Every time that he smiles and he tells me something new or that he has noticed something, I’m really proud – because that’s a big change,” Padilla said.

Padilla has this advice for other parents:

“I think if you look for help, it’s better,” she said. “It makes a big difference.”

Gorton said the critical time for early childhood intervention is up to the age of six. Twenty-five to 40 hours of intensive therapy each week can be the stepping stone for a child having independence later in life.

For a list of autism signs in children, click here. You can also find out more about services available to parents of autistic children by clicking here.