Japanese version of home form of the ADHD-RS: An evaluation of its reliability and validity

Using the Japanese version of home form of the ADHD-RS, this survey attempted to compare the scores between the US and Japan and examined the correlates of ADHD-RS. We collected responses from parents or rearers of 5977 children (3119 males and 2858 females) in nursery, elementary, and lower-secondary schools. A confirmed factor analysis of ADHD-RS confirmed the two-factor solution (Inattentive and Hyperactive-Impulsive) same as previous studies. ADHD-RS scores were not related to IQ, but were negatively associated with standardized achievement test scores. Males showed stronger ADHD tendencies than did the females, and the scores ended to decline as the children grew older. Japanese children scored lower than did their US children in Hyperactive-Impulsive among all of the sex-age groups. Japanese version of home form of the ADHD-RS was developed with good reliability and validity. More researches of ADHD in Japanese children are required.