Objective QbTest and subjective evaluation of stimulant treatment in adult attention deficit-hyperactivity disorder

Abstract

Purpose: To evaluate the QbTest as an objective measure versus self-reported ADHD Rating Scale (ADHD-RS) before and during stimulant treatment in adults with ADHD.

Patients and methods: We used the subjective ADHD Rating Scale (ADHD-RS), and the objective computerized QbTest, which is a 20-minute unconditional identical pairs test that measures attention, impulsivity, and also hyperactivity using a motion-tracking system. Patients were assessed before (baseline) and during medical treatment with stimulants (follow-up) in an observational study design.

Results: Data of n=145 patients at baseline and n=82 patients at follow-up were analyzed. There were significant symptom reductions on all symptom domains, but correlations between the tests were weak. Improvement on the QbTest was independent of the patient's age, gender, educational level, ADHD subtype, co-morbid disorders, and use of other medications. Patients with worst QbTest results at baseline showed most improvement at follow-up. The QbTest was more sensitive to medication effects than the ADHD-RS. QbTest objectified clinical significant medication effect in 54% of patients who subjectively did not report any clinical effects.

Discussion: Symptoms dimensions of objective and subjective tests refer to different psychological constructs.

Conclusion: The QbTest is a valuable addition to existing subjective measures to assess medication effects in ADHD patients who have difficulties reporting treatment effects.

Keywords: Attention deficit-hyperactivity disorder (ADHD); Methylphenidate; Psychometry and assessments in psychiatry; Treatment effectiveness.