1,067 infants who were born between 2009 and 2011 who underwent the 18 month old health checkup in the city of Okaya were examined for autism spectrum disorder, a type of developmental disorder. 3.1% of children in Japan are diagnosed with autism spectrum disorder by age six when they enter elementary school. The study found that children who were later diagnosed with autism spectrum disorder exhibited signs during the 18 month health checkup.

The study conducted by Associate Professor Daimei Sasayama, Professor Hideo Honda, Professor Shinsuke Washizuka of the Department of Child and Adolescent Developmental Psychiatry and Professor Tetsuo Nomiyama of the Department of Preventive Medicine and Public Health with the help of Okaya City and Shinano Medical Welfare Center found that the 18 month health checkup which is free of charge and available to all children born in Japan is an effective method to screen for risk factors of physical and social communication difficulties associated with autism spectrum disorder.

This research was published online on July 21, 2020 in the Journal of Autism and Developmental Disorders, one of the most prestigious international autism journals.

Title: Brief Report: Cumulative Incidence of Autism Spectrum Disorder Before School Entry in a Thoroughly Screened Population
Author: Daimei Sasayama· Tetsuya Kudo · Wakako Kaneko · Rie Kuge · Noriaki Koizumi · Tetsuo Nomiyama · Shinsuke Washizuka · Hideo Honda
Journal: Journal of Autism and Developmental Disorders (online publication)
URL: https://link.springer.com/article/10.1007/s10803-020-04619-9