ABSTRACT
BACKGROUND: The d2-R test is a cancellation test developed in Germany to measure concentration and attention. This study examined the validity of the d2-R test for Japanese adolescents in comparison with German standardized data. METHODS: Japanese junior high school students (n = 121; 61 girls, 60 boys) participated in this study. The students' performance scores in the d2-R test were compared with their daily attentiveness and hyperactivity/impulsiveness assessments conducted by the teachers. The assessments were evaluated using the attention deficit-hyperactivity disorder rating scale, fourth edition (ADHD-RS)-IV. The comparison with German counterparts was also made. RESULTS: Students who were rated as less attentive and more hyperactive/impulsive performed more slowly and committed more errors in the d2-R test. Although there were no sex differences in any of the d2-R parameters, male students were rated higher than female students in all of the ADHD-RS-IV scores. Japanese adolescents outscored German counterparts on speed, concentration, and carefulness. CONCLUSION: The concurrent validity of the d2-R test is confirmed. It is an appropriate index to measure the sustained and focused attention of Japanese adolescents. The present research merits attention as the first investigation of the d2-R test conducted for Japanese adolescents.
