In the Netherlands, the ADHD Questionnaire (ADHD-Q; Scholte & Van der
Ploeg, 1998) is without any doubt the most frequently employed content-specific
rating scale for measuring symptoms of ADHD in children. The ADHD-Q assesses
the frequency of DSM-defined ADHD-symptoms of inattention, hyperactivity,
and impulsivity. Previous research has shown that this rating scale is
reliable in terms of internal consistency (with Cronbach’s alpha generally well
above 0.80) and temporal stability (with a 2-weeks test-retest correlation of
0.95; Scholte & Van der Ploeg, 1998)