A Q-score of 1.25 or higher on at least one of the measured parameters in a Quantified Behavioural Test (QbTest) may suggest the presence of ADHD indicators.
Understanding QbTest Scores and ADHD Indicators
The QbTest is an objective and computer-based test that measures core ADHD symptoms: inattention, impulsivity, and hyperactivity. It provides data on an individual's performance compared to others of the same age and gender.
What is a Q-Score?
Q-scores are standardized scores, also known as z-scores, which represent how many standard deviations an individual's performance deviates from the mean performance of people without ADHD in their age and gender group. A higher Q-score indicates a greater deviation from typical behavior, particularly in areas related to attention, impulse control, and activity levels.
The Indicative Threshold
For adults, a Q-score of 1.25 or higher on any of the core parameters (attention, impulsivity, or motor activity) is considered a significant deviation that may point towards ADHD.
Here’s a quick overview:
| Parameter Type | Indicative Q-Score | Interpretation |
|---|---|---|
| Attention | ≥ 1.25 | May indicate difficulties with sustained focus. |
| Impulsivity | ≥ 1.25 | May suggest challenges with inhibiting immediate responses. |
| Motor Activity | ≥ 1.25 | May point to higher-than-average movement or restlessness. |
Important Considerations for Diagnosis
It is crucial to understand that a QbTest is not a standalone diagnostic tool for ADHD. While a Q-score of 1.25 or above is a strong indicator, it must always be interpreted within a comprehensive clinical assessment.
Key points regarding its role in diagnosis:
- Part of a Broader Assessment: The QbTest provides objective data that complements other diagnostic methods, such as clinical interviews, behavioral observations, symptom checklists, and information gathered from family members or teachers.
- Objective Measurement: It offers an objective measure of core symptoms, which can be particularly useful in cases where self-report or observational data might be subjective.
- Monitoring Treatment Efficacy: Beyond diagnosis, QbTest results can also be used to monitor the effectiveness of treatment over time, showing whether interventions are helping to normalize attention, impulsivity, and activity levels.
- Excluding Other Conditions: A comprehensive evaluation helps differentiate ADHD symptoms from those caused by other medical or psychological conditions.
How the QbTest Works
During a QbTest, participants typically complete a sustained attention task on a computer while their movements are tracked. The test measures:
- Inattention: Errors of omission (missing targets).
- Impulsivity: Errors of commission (responding when they shouldn't).
- Hyperactivity: Overall motor activity during the test.
These objective measurements, when compared to normative data, provide the Q-scores that inform clinicians about potential ADHD symptom presentation. For further details on the test and its application, you can explore resources such as studies on The Quantified Behavioural Test Plus (QbTest+) in adult ADHD.
