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

Iori and colleagues translated the ADHD Rating Scale home form into Japanese.

Parents filled out the 18-item checklist about their children’s ADHD symptoms.

The team checked if scores were reliable and if the two-factor structure held.

The Japanese parent form worked. Internal consistency was acceptable.

The same two factors—inattention and hyperactive-impulsive—showed up.

Japanese parents rated hyperactive-impulsive behaviors lower than U.S. norms.

Ohnishi et al. (2010) ran the same checks on the teacher version the same year. Both forms passed, giving Japan a matched home-school pair.

Davis et al. (2011) later showed the two-factor model also fits Japanese university students. This means the structure holds from childhood to adulthood.

Hongo et al. (2024) followed the same translation steps with the Camouflaging Autistic Traits Questionnaire. Their caution about subscale drift reminds us to watch for cultural tweaks even after a scale “passes.”

You now have a free, validated parent scale for Japanese-speaking families. Use it at intake, re-eval, or telehealth. Expect lower hyperactivity scores than U.S. norms—don’t over-pathologize. Pair it with the teacher form for a fuller picture.