The Quantified Behavioral Test—A Confirmatory Test in the Diagnostic Process of Adult ADHD?

Abstract

The differential diagnosis of attention deficit hyperactivity disorder (ADHD) in adulthood is complicated by comorbid disorders, but also by the overlapping of main symptoms such as inattentiveness, impulsivity, and hyperactivity with other disorders. Neuropsychological tests like continuous performance tests (CPT) try to solve this dilemma by objectively measurable parameters. We investigated in a cohort of n=114 patients presenting to an ADHD outpatient clinic how well a commercially available CPT test (QbTest ®) can differentiate between patients with ADHD (n=94) and patients with a disconfirmed ADHD diagnosis (n=20). Both groups showed numerous comorbidities, predominantly depression (27.2% in the ADHD group vs. 45% in the non-ADHD group) and substance-use disorders (18.1% vs. 10%, respectively). Patients with ADHD showed significant higher activity (2.07 ± 1.23) than patients without ADHD (1.34 ± 1.27, dF=112; p=0.019), whereas for the other core parameters, inattention and impulsivity no differences could be found. Reaction time variability has been discussed as a typical marker for inattention in ADHD. Therefore, we investigated how well ex-Gaussian analysis of response time can differentiate between ADHD and other patients, showing, that it does not help to identify patients with ADHD. Even though patients with ADHD showed significantly higher activity, this parameter differed only poorly between patients (accuracy AUC 65% of an ROC-Curve). We conclude that CPTs do not help to identify patients with ADHD in a specialized outpatient clinic. The usability of this test for differentiating between ADHD and other psychiatric disorders is poor and a sophisticated analysis of reaction time did not decisively increase the test accuracy.

A Within-Sample Comparison of Two Innovative Neuropsychological Tests for Assessing ADHD

“…These findings apply for the hyperactivity factor in both CPTs as well as the underlying variables of hyperactivity in Nesplora Aquarium and the Qb-Test. These results are supported by the finding that ADHD patients show significant higher activity than patients without ADHD [ 19 ]. While the hyperactivity factors of both tests are independent, they nevertheless seem to be related to one of the most valid clinical symptom components.…”

“…Inattention, mainly driven by test performance, is a basic factor, which overlaps between the two tests in each subject. As it fails to predict clinical parameters, this highlights the previously described problem in linking subjective and objective methods in diagnosing ADHD [ 19 ]. A very interesting test parameter is hyperactivity, which reflects current ADHD symptoms in both tests, while in the Qb-Test it is additionally associated with childhood ADHD symptoms.…”

“…However, the accuracy and usefulness of CPTs in ADHD patients are critically discussed due to their lack of sensitivity and specificity [ 17 ]. The predictive power of these measures in differentiating ADHD patients from controls, or patients with other mental disorders, is insufficient [ 18 , 19 ]. CPT variables and ADHD symptoms are associated only to a small amount, as only 52% of ADHD patients have correctly been classified as ADHD by using a CPT [ 20 ].…”

The Impact of Methylphenidate on QbTest Performance of Children with ADHD: A Retrospective Clinical Study

“…9 Thus, the cardinal parameters inform on differences between a patient's raw score and the score of an age and gender-matched control. 37,38 A Q-score of 1.5 or higher is interpreted as atypical 34 and a Qscore of 1.5 corresponds to the 93 rd percentile. 37 The value of the Q-score ranging from 1.1 to 1.4 is interpreted as slightly atypical.…”

Predicting adult Attention Deficit Hyperactivity Disorder (ADHD) using vocal acoustic features

“…Future studies with larger sample size may be able to predict ADHD with higher precision and possibly be able to better differentiate ADHD participants from participants with low or moderate ADHD symptoms. Likewise, other studies investigating potential biomarkers of ADHD point to a restricted differentiation from clinical controls such as studies of neurological tests in combination with actigraphy [71-74], meta-analyses evaluating fMRI [75] and resting-state fMRI studies to predict ADHD respectively [76, 77].…”