Weak impacts of neuropsychological measures on symptoms of attention deficit hyperactivity disorder in university students.

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is involved in broad neuropsychological domains, including response inhibition, timing, delay aversion, sustained attention, and working memory. This study aimed to examine the relationship between ADHD symptoms and neuropsychological measures in university students.

METHODS

A total of 167 graduate and undergraduate students participated in the study. Neuropsychological characteristics were comprehensively assessed using stop signal, delay discounting, time discrimination, sensorimotor synchronization, continuous performance, and digit span tasks. ADHD symptoms were assessed using the Japanese version of Conners' ADHD Rating Scale.

RESULTS

ADHD symptoms were significantly correlated with some neuropsychological measures, such as the false alarm rate in the continuous performance task; however, these correlations were not strong. In the multiple regression analyses, models including neuropsychological measures were significantly associated with ADHD symptoms, but the coefficients of determination ranged from 0.06 to 0.08. Thus, most of the variance in ADHD symptoms was not explained by neuropsychological measures.

CONCLUSION

These findings suggest that the impact of each neuropsychological measure on ADHD symptoms was weak in university students, and ADHD symptoms cannot be explained by neuropsychological characteristics, which are currently considered core characteristics of ADHD. In addition, ADHD symptoms assessed by self-rating questionnaire in the non-clinical sample might not reflect the degree of real ADHD severity.