Researchers have shown for the first time that if a child is diagnosed with autism as early as 18 months of age, offering the toddler age-appropriate, effective therapy can lead to raised IQ levels and improved language skills and behavior.

“Early intervention can be very effective for toddlers with autism,” says Geraldine Dawson, chief science officer of the advocacy group Autism Speaks, and one of the two lead authors of a study published Monday in the journal Pediatrics.