Fewer than one out of every child who have Autism Spectrum Disorder (ASD) were diagnosed before age 2, says a new study by National Institute of Mental Health.

According to experts earlier detection of ASD makes treatment easier and aids in developmental programs. It also reduces need for extra medication or health services in later life.

The study says that most children who were diagnosed with ASD after 5 years tend to use many medications and health care services.

For the study, researchers interviewed parents of nearly 4,000 children who had confirmed diagnosis of ASD or intellectual disabilities.

The researchers found that less than 20 percent of children with autism were diagnosed by age 2.

According to Centers for Disease Control and Prevention (CDC), Autism Spectrum Disorders are a group of developmental disabilities that can cause significant social, communication and behavioral challenges. People with ASD handle information in their brain differently than other people. 

"Research tells us that children who start intervention earlier do better in the long run. This report found that the majority of children were 5 years or older when they were first identified. We can reliably diagnose autism by 24 months, so professionals need to do a better job, including screening all children at 18 and 24 months," said Geraldine Dawson, chief science officer for Autism Speaks, reports Health Day.

The study says that children diagnosed with ASD either before or after 5 years used health care services like social skills training and speech or language therapy to the same extent.

"Our data indicate that many children with autism -- the majority -- are getting some sort of services such as speech or other individual-based interventions. That is great news," said Lisa Colpe of the National Institute of Mental Health in Bethesda, reports WebMD.

Over one half of all school aged Children with Special Health Care Needs (CHSCN) with ASD use at least one psychotropic medication, one third use stimulant medications; one-quarter use anti-anxiety or mood-stabilizing medications, and one-fifth use antidepressants, says NCHS data brief.

"Be involved with practitioners who are experts in autism at the first concern, and if a diagnosis isn't given, ongoing monitoring, assessment, and checking in can help guide parents through the developmental stages," Amy Keefer, a clinical psychologist in the Kennedy Krieger Institute's Center for Autism and Related Disorders in Baltimore, told WebMD.

According to CDC, In the US, 1 in 88 children and 1 in every 54 boys are born with autism.