Introduction: Why QbTest Matters in ADHD Diagnosis

Attention-Deficit/Hyperactivity Disorder (ADHD) is traditionally diagnosed using interviews and rating scales such as the DSM-5 or ICD-11 criteria. While these remain essential, they are based on subjective reports from parents, teachers, and clinicians. This subjectivity often leads to either overdiagnosis or underdiagnosis.

The QbTest—a computer-based test approved by regulatory authorities in several countries—offers an objective method of measuring ADHD symptoms. By tracking activity, inattention, and impulsivity, it provides measurable data that complements clinical judgment. This article explains how to interpret QbTest results and why it is valuable for diagnosis and treatment monitoring.

What is QbTest in ADHD?

The QbTest is a continuous performance test (CPT) combined with an activity tracker. While the patient completes a computerized task, the system records responses and physical movements. This dual approach makes it unique because it captures both cognitive and behavioral aspects of ADHD.

The test evaluates three domains:

• QbActivity – Measures motor restlessness and hyperactivity.

• QbInattention – Assesses ability to maintain focus and complete tasks.

• QbImpulsivity – Captures premature or uncontrolled responses.

Each domain produces raw scores, percentiles, and Q-scores, which allow clinicians to compare the patient with a normative group based on age and gender.

Understanding QbTest Scores

1. Raw Scores

These are the unprocessed results generated during the test. They provide the basic data but require standardization to be clinically meaningful.

2. Percentiles

Percentiles compare the individual with peers:

• Example: A 93rd percentile for activity means the child is more active than 93% of peers in the reference group.

• Higher percentiles usually indicate greater deviation from typical behavior.

3. Q-Scores

Q-scores express how far someone’s performance deviates from the average (mean).

• Q = 0: Exactly average.

• Q = 1.1 (≈ 86th percentile): Slightly abnormal.

• Q = 1.5 (≈ 93rd percentile): Atypical and clinically significant.

Interpretation Guide:

• 0–1.0 Q-score → Within normal limits.

• 1.1–1.4 Q-score → Slightly abnormal; may raise suspicion.

• ≥1.5 Q-score → Atypical; strongly suggests ADHD-related impairment.

Clinical Application: Using QbTest for Diagnosis

The QbTest does not replace clinical interviews or rating scales. Instead, it acts as an objective supplement that strengthens diagnostic confidence. For example:

• A child showing high impulsivity Q-scores may confirm parent-reported difficulties.

• A teenager with borderline attention scores might highlight subtle inattention otherwise missed in routine evaluations.

QbTest in Treatment Monitoring

One of the strongest advantages of QbTest is its ability to track progress over time.

• A 0.5 reduction in Q-score (half a standard deviation) across domains is considered a clinically significant improvement.

• Clinicians can compare before-and-after results to evaluate effectiveness of medication, behavioral therapy, or lifestyle interventions.

This objective feedback reassures families that progress is measurable, even when day-to-day changes feel less obvious.

Benefits of QbTest in ADHD Assessment

• Objective Data: Reduces reliance on subjective observations.

• Comprehensive: Separately measures hyperactivity, inattention, and impulsivity.

• Age- and Gender-Normed: Ensures fair comparisons.

• Treatment Monitoring: Helps evaluate clinical response to interventions.

• Patient Engagement: Visual reports make it easier for families to understand ADHD.

Limitations to Consider

• QbTest should never be used as a standalone diagnostic tool.

• Results can be influenced by anxiety, fatigue, or poor test motivation.

• Clinical context, psychosocial history, and rating scales remain essential.

Conclusion: QbTest as a Game-Changer in ADHD Care

The QbTest bridges the gap between subjective impressions and objective measurements. By providing percentile ranks and Q-scores, it makes ADHD assessment more precise and treatment monitoring more transparent.

For clinicians, it adds a valuable dimension of evidence-based objectivity. For families, it provides a clear, data-driven explanation of their child’s struggles.

In the evolving landscape of digital psychiatry, tools like QbTest represent the future—bringing ADHD care closer to the rigor of physical health monitoring.

✦ About the Author

I’m Dr. Srinivas Rajkumar T, MD (AIIMS, New Delhi), Consultant Psychiatrist at Mind and Memory Clinic, Apollo Clinic, Velachery, Chennai (Opp. Phoenix Mall).
My expertise includes ADHD, neurodevelopmental disorders, neuromodulation therapies (rTMS, tDCS, neurofeedback), and digital brain-based assessments like QbTest.

📞 Contact: +91 85951 55808
🌐 Visit: srinivasaiims.com