The Quantified Behavioural Test Plus (QbTest+) in adult ADHD

Abstract The Quantified Behavioural Test Plus (QbTest+) is widely used in clinical practice to assess patients with attention-deficit hyperactivity disorder (ADHD). This study mapped its behaviour in a group of adults with ADHD. Does it signal problems with impulsivity, attention and/or activity? To what extent are patients’ self-reported problems reflected in QbTest performance? Does Qb testing foretell the future, as reflected in the patients’ and clinicians’ judgements 4 years later? We here recorded the three QbTest+ cardinals–QbActivity, QbImpulsivity and QbInattention – in 67 consecutive ADHD patients diagnosed in adulthood. Among the 54 patients who medicated as usual on the day of testing, 35 (65%) scored above the clinical cut-off (Q-score ≥ 1.25) on at least one of the QbTest+ cardinals. Out of the 13 patients who suspended medication prior to the test, 11 (85%) scored above the clinical cut-off on at least one of the Qb-variables. There were modest associations between QbTest+ cardinals and symptom self-ratings [Brown ADD scale (BADDS); Adult Self-Report Scale (ASRS)]. Forty-one patients completed a second QbTest+ approximately 4 years after the first. Performance was improved on the follow-up test and fewer patients scored in the clinical range (34%). The scores on the QbInattention cardinal at baseline correlated positively with BADDS and ASRS self-ratings at the 4-year follow-up.