SYDNEY, Aug. 9 (Xinhua) -- High levels of anxiety are being found in autistic children as young as 5 in Australian schools, with the feelings increasing with age, according to a study touted as the first of its kind.

"We're now finding that almost three-quarters of children with autism are impacted by high anxiety levels," Griffith University researcher Dawn Adams, lead author of the findings, said in a statement on Thursday.

The researchers from the university's center focusing on autism, a developmental disorder including difficulties with social interaction and restricted behavior, analyzed anxiety symptoms of more than 90 children aged 5-12 years in mainstream and special schools.

More than a quarter of children with autism were scared of making mistakes at school and almost a third hesitated in starting a task or worried about understanding it first, which can "impact upon their learning experience and reduce their self-esteem", reported the researchers, whose findings were published in the Journal of School Psychology.

Still, there is "scant research exploring anxiety in children with autism at school and almost no work looking at how anxiety might differ in a school setting to that at home", said Adams.

"Understanding anxiety in children on the autism spectrum within the school context is critical to develop support and identifying strategies to minimize the impact on education, learning and health."

About one in 200 Australians are affected by autism and most of them are boys, according to health industry figures. The symptoms may be noticeable from the age of 2 but a firm diagnosis usually cannot be made until a child is 3.

"We know that anxiety can impact upon a child's educational performance, affect recall of academic knowledge and result in poorer academic grades and lower overall school performance," said Adams.

"Working together across home and school to identify, recognize and support anxiety in children with autism should therefore increase academic outcomes and success."