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

QbTest for Monitoring Medication Treatment Response in ADHD: A Systematic Review

Introduction

Attention deficit hyperactivity disorder (ADHD) is considered one of the most common neurodevelopmental disorders in childhood and adolescence. Pharmacological treatment plays an important part in the therapy of the disorder and verifying the effectiveness of ADHD medication is essential throughout the course of treatment. QbTest is a computerized test, for which intended use is to provide healthcare professionals with objective measurements of hyperactivity, impulsivity, and inattention to aid in the clinical assessment of ADHD and the evaluation of treatment interventions.

Methods

A systematic review of relevant articles was conducted for which QbTest was used for monitoring medication treatment response in ADHD. Literature published between 2004 and 2023 was appraised.

Results

A total of 15 studies were included in the review. Thirteen articles involved subjects diagnosed with ADHD and two studies that were related to the disorder, which evaluated QbTest in medication treatment response. Changes in QbTest data such as Q-scores, effect size, or improvement/deterioration of QbTest variables were evaluated. A clinically relevant decrease in QbTest Q-scores was found in the majority of the studies when treated with any type of ADHD medication in therapeutic doses, both in comparison to placebo and when compared from baseline to endpoint treatment.

Conclusion

QbTest can distinguish pharmacological treatment effects within hours of pharmacological titration and can be used for monitoring of long-term treatment of ADHD. A need for optimization and individualization of medication treatment response could be addressed with access to objective measures in ADHD management.

Effects of one single-dose methylphenidate compared to one single-dose placebo on QbTest performance in adults with untreated ADHD: a randomized controlled trial

BACKGROUND

Treatment of adults with attention-deficit/hyperactivity disorder (ADHD) primary involves methylphenidate (MPH). Earlier studies have identified placebo responders to increase toward the end of the treatment periods. However, little is known about the immediate effects of placebo on the core symptoms of ADHD in adults. The present study aimed to examine the effects of one single-dose MPH compared to one single-dose placebo during clinical assessments with continuous performance tests (CPT).

METHODS

In a randomized study with cross-over design, 40 adults between 19 and 64 years (72.5% women) with untreated ADHD were consecutively enrolled. The study comprised two trial days with four days in between. The QbTest was performed twice on the same day, before and 80 min after intake of one single-dose 20 mg immediate release methylphenidate (IR-MPH) and with one single-dose placebo, in randomized order.

RESULTS

Performance improved in QbInattention, F (3, 117) = 38.25, p < 0.001, after given IR-MPH (mean diff = 1.14) and after placebo (mean diff = 0.60) with the effect sizes 1.17 and 0.63 respectively. IR-MPH improved performance in QbActivity (mean diff = 0.81, p < 0.001) and QbImpulsivity (mean diff = 0.46, p < 0.04). The proportion of improvements (a decrease by ≥ 0.5 Qb-score) in the parameters QbInattention, QbActivity and QbImpulsivity were 90%, 60% and 52.5%, respectively. After given placebo, corresponding proportions were 60%, 30% and 35%, respectively.

CONCLUSIONS

There seems to be an immediate placebo response in the core symptom inattention. The effect of placebo cannot be ruled out and must be taken in consideration during drug trials with continuous performance tests (CPTs).

TRIAL REGISTRATION

ClinicalTrials.gov; Identifier: NCT02473185.

The Structure and Diagnostic Accuracy of the QbTest in Pediatric ADHD: A Retrospective Clinical Study

OBJECTIVE

The QbTest that combines a continuous performance task (CPT) with a motion-tracking system may help identify attention deficit hyperactivity disorder (ADHD). This study examined the structure and diagnostic ability of the QbTest in children and adolescents.

METHOD

Retrospective data from 1,274 children and adolescents were analyzed. The study assessed data on a principal component analysis (PCA), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The QbActivity component included the variables micro-events, distance, area, and time active; the QbImpulsivity included normalized commissions and commissions (anticipatory errors were added in a version for 6-12-year-olds only); and the QbInattention included omissions, reaction time, and reaction time variation. Sensitivity ranged between 22% and 50%, specificity 79% and 96%, PPVs 40% and 95%, and NPVs 24% and 66%.

CONCLUSION

The structure of the QbTest with three cardinal parameters and nine/ten CPT and motion analysis variables was supported. The diagnostic accuracy was found to be poor to moderate. Given that this is a retrospective study, the interpretation of diagnostic accuracy should be considered within this context.

A preliminary study of white matter correlates of a laboratory measure of attention and motor stability in attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a complex behavioral disorder, often difficult and time consuming to diagnose. Laboratory assessment of ADHD-related constructs of attention and motor activity may be helpful in elucidating neurobiology; however, neuroimaging studies evaluating laboratory measures of ADHD are lacking. In this preliminary study, we assessed the association between fractional anisotropy (FA), a measure of white matter microstructure, and laboratory measures of attention and motor behavior using the QbTest, a widely used measure thought to improve clinician diagnostic confidence. This is the first look at neural correlates of this widely used measure. The sample included adolescents and young adults (ages 12-20, 35% female) with ADHD (n = 31) and without (n = 52). As expected, ADHD status was associated with motor activity, and cognitive inattention and impulsivity in the laboratory. With regard to MRI findings, laboratory observed motor activity and inattention were associated with greater FA in white matter regions of the primary motor cortex. All three laboratory observations were associated with lower FA in regions subserving fronto-striatal-thalamic and frontoparietal (i.e. superior longitudinal fasciculus) circuitry. Further, FA in white matter regions of the prefrontal cortex appeared to mediate the relationship between ADHD status and motor activity on the QbTest. These findings, while preliminary, suggest that performance on certain laboratory tasks is informative with regard to neurobiological correlates of subdomains of the complex ADHD phenotype. In particular, we provide novel evidence for a relationship between an objective measure of motor hyperactivity and white matter microstructure in motor and attentional networks.

Contrasting expectancy effects with objective measures in adults with untreated ADHD during QbTest

Expectancy has been associated with neuropsychological assessments and cognitive performance. However, little is known about the effects of expectations in clinical assessments during drug trials with continuous performance tests (CPTs). In a randomized, double-blind study with cross-over design, we examined if the participants' self-reported expectations changed after one-single dose immediate release methylphenidate (MPH) and after one-single dose placebo during the QbTest. Forty adults between 19 and 64 years (72.5% women) with un treated ADHD were consecutively enrolled in the study and their assessments of expected performance, mental effort, perceived performance and help from the pill were analyzed. The study comprised two trial days with four days in between. The QbTest was performed twice on the same day, before and 80 minutes after a pill. Our study demonstrates that there were expectancy effects during CPTs. Participants reported lower mental effort and improved their performance in the coronary parameter QbInattention both after MPH and after placebo. No significant differences in expected performance were reported. The participants seemed to show some uncertainty when assessing their expected performance, however, they could evaluate their performance afterwards. In clinical practice, the focus should be on reinforcing patients' expectations in order to increase treatment effects.

ASD with ADHD vs. ASD and ADHD alone: a study of the QbTest performance and single-dose methylphenidate responding in children and adolescents

BACKGROUND

The continuous performance task (CPT) may help identify coexistent attention deficit hyperactivity disorder (ADHD) in autism spectrum disorder (ASD). The Quantified behavior Test (QbTest) combines a CPT and motion-tracking data to assess ADHD symptoms. This study aimed to evaluate the QbTest performance of children and adolescents with ASD plus ADHD, including estimating the effects of single-dose methylphenidate (MPH). To achieve these aims, (1) the QbTest performances were evaluated in ASD alone, ASD plus ADHD, and ADHD alone, and (2) the effects on the QbTest performance of single-dose MPH before and after intake were estimated across the groups. It was assumed that the ASD plus ADHD performance, including the MPH response, would preferably resemble the performance in ADHD alone, rather than ASD alone.

METHODS

Retrospective data were analyzed for 482 children and adolescents: 69 with ASD alone, 142 with ASD plus ADHD (ASD/ADHD), and 271 with ADHD alone. For 343 subjects, the QbTest was performed before and up to four hours after a single-dose MPH intake. A summary index of the CPT and motion-capture data was provided for QbTest cardinal parameters.

RESULTS

Of 12 QbTest parameters assessed before given MPH, the ASD/ADHD group had scores in line with the ASD group regarding four parameters and the ADHD group regarding nine parameters. Significant differences between groups were seen with respect to QbInattention (p > 0.05); the lowest scores in ASD and the highest in ADHD. Those with ASD/ADHD and ADHD had similar QbActivity and QbImpulsivity scores, but significantly higher than those with ASD. After MPH intake, scores for QbActivity decreased similarly in ASD/ADHD and ADHD, as well as scores for QbImpulsivity. QbImpulsivity increased in ASD. QbInattention scores decreased similarly in all groups after MPH intake.

CONCLUSIONS

Children and adolescents with ASD plus ADHD exhibited more atypical QbTest performances than those with ASD alone, while most of their performances were similar to those observed in ADHD alone. In addition, a single dose of MPH mitigated attention deficits and decreased hyperactivity while improved impulsivity in these children. Prospective studies should further clarify the role of the QbTest in the diagnostic and therapeutic interventions in ASD with ADHD.

A review of objective assessments for hyperactivity in attention deficit hyperactivity disorder

Hyperactivity is one of the three core symptoms of attention deficit hyperactivity disorder (ADHD) that is a common childhood mental disorder. Objective assessments of hyperactivity are seldom utilized compared with measures of inattention and impulsivity during clinical diagnosis and evaluation. Acceleration-sensitive devices (e.g., Actigraph) and motion tracking systems (e.g., QbTest) are two main groups of devices that can be used to objectively measure hyperactivity. The Actigraph and QbTest have good discriminant validity, convergent validity, and sensitivity to the effects of stimulants. Furthermore, the assessment setting (i.e., research laboratory, school, or home) can greatly influence the presence and severity of hyperactivity. Nevertheless, objective assessments for hyperactivity have poor ability to distinguish ADHD from other disorders, or among the three types of ADHD. Thus, further studies are needed to assess objective measurements of hyperactivity in terms of discriminant and convergent validity, test-retest reliability in different settings, and correlations with brain activity.