01 · The method
What a Continuous Performance Test is
A Continuous Performance Test (CPT) is a standardized, computer-based task that has been used in attention research and clinical evaluation for decades. Simple targets appear on screen; you respond to some and withhold on others, for several minutes.
The task is intentionally a little monotonous — that is the point. Sustaining attention on something low-stimulation is exactly where attention difficulties surface. The system records every response and its timing, then summarizes them into age-referenced measures a clinician can interpret.
Crucially, a CPT is supporting data — one objective input a clinician weighs alongside your intake and history. Professional guidelines are explicit that ADHD is diagnosed through clinical evaluation against DSM-5-TR criteria, not by any single test.[4][6]
The assessment, step by step
1.DSM-5 intake
A structured questionnaire across the symptom domains, onset, settings, and impairment — about 8 minutes.
2.The attention test
A ~5-minute standardized attention task, from home, no appointment.
3.Clinician review
A licensed clinician reads your results against age norms within 24 hours.
4.Diagnosis & care plan
After a short online session, your diagnosis and care plan — within 72 hours.
02 · What the test measures
Three windows into attention
Each metric is a specific, well-studied behaviour. Together they describe how attention and impulse control actually hold up under load.
Attention (omission errors)
Missed targets and lapses across a long, monotonous task — a direct read on how steadily attention is held when it matters least and slips most.
Impulse control (commission errors)
Responses to signals you were supposed to withhold — the tendency to act before checking, a core feature of the impulsive presentation.
Reaction-time variability
Not just how fast, but how variable. Reaction-time variability is one of the most robust, well-studied signals of attentional instability.
03 · ADHD in adults
Often missed, rarely outgrown
ADHD is not only a childhood condition. An estimated 4.4% of U.S. adults meet criteria for ADHD, yet a large share are undiagnosed and untreated.[2] In adulthood the visible hyperactivity of childhood often becomes internal restlessness, and the difficulty shifts toward planning, follow-through, time management, and emotional regulation.[5]
Many adults coped for years through effort and workarounds, only hitting a wall when a life change removed the structure that had been holding them together. Because self-report alone can be coloured by anxiety, insight, and memory, an objective performance measure adds signal a questionnaire can’t — which is precisely where a CPT earns its place.
How adult ADHD shows up
- • Internal restlessness rather than overt hyperactivity
- • Trouble with planning, follow-through, and time
- • Emotional intensity and difficulty shifting gears
- • A pattern that traces back to childhood[6]
04 · ADHD in children
Common, and best assessed with structure
ADHD is one of the most common neurodevelopmental conditions of childhood. As of 2022, about 1 in 9 U.S. children aged 3–17 — roughly 7.1 million (11.4%) — had ever been diagnosed with ADHD.[1] In children, hyperactivity is often more visible, and difficulties surface loudly in structured settings like the classroom.
The American Academy of Pediatrics recommends diagnosing ADHD using DSM-5 criteria and information gathered across settings — an approach a structured intake is built to support.[4] For a child, a parent completes the intake and manages everything; the child takes a short, game-like test, and a licensed clinician reviews the results against age-appropriate norms.
Why norms are age-specific
A child’s results are compared against other children, not adults, so “more difficulty than expected” always means relative to the right peer group. The measurement is the same idea at any age; the benchmark adapts.
05 · Why objective data adds signal
Performance, not perception
Questionnaires ask how you think you do; a CPT records how you actually perform, moment to moment. One of the most-studied signals is reaction-time variability — the wobble in how fast you respond from one moment to the next. A meta-analytic review of 319 studies found that reaction-time variability is reliably elevated in ADHD, making it one of the field’s most robust behavioural markers.[3]
That same research is a good example of why we’re careful with claims: elevated variability is characteristic of ADHD but not unique to it, so it can’t stand alone as a diagnosis.[3] That is exactly why a licensed clinician interprets your objective results together with your intake and history, rather than reading a number in isolation.
Performance-based
Behaviour a person can’t easily narrate or fake.
Norm-referenced
Compared to what’s typical for your age.
DSM-5-aligned
Framed the way a diagnosis is actually made.
06 · What it can — and can’t — tell you
Honest about the limits
Objective testing is powerful precisely because we’re clear about what it is — and isn’t.
It can
- • Give a clinician objective, norm-referenced performance data.
- • Add signal a self-report questionnaire can’t.
- • Provide a repeatable baseline to measure change over time.
Vextara is decision support for a licensed clinician — not a diagnosis or a substitute for care. Attention difficulties can also stem from anxiety, depression, sleep, and other conditions, which is a core reason a qualified human makes the call.[5]
References
Sources
- 1Centers for Disease Control and Prevention. Data and Statistics on ADHD (2022 National Survey of Children’s Health). www.cdc.gov/adhd/data
- 2Kessler RC, et al. The Prevalence and Correlates of Adult ADHD in the United States: Results From the National Comorbidity Survey Replication. American Journal of Psychiatry. 2006;163(4):716–723. psychiatryonline.org/doi/10.1176/ajp.2006.163.4.716
- 3Kofler MJ, et al. Reaction time variability in ADHD: A meta-analytic review of 319 studies. Clinical Psychology Review. 2013;33(6):795–811. www.sciencedirect.com/science/article/abs/pii/S0272735813000871
- 4Wolraich ML, et al. (American Academy of Pediatrics). Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of ADHD in Children and Adolescents. Pediatrics. 2019;144(4):e20192528. publications.aap.org/pediatrics/article/144/4/e20192528/81590
- 5National Institute of Mental Health. Attention-Deficit/Hyperactivity Disorder (ADHD). www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd
- 6American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). 2022. www.psychiatry.org/psychiatrists/practice/dsm
This page is an educational overview and not medical advice. Prevalence figures and clinical guidance are drawn from the cited public health bodies and peer-reviewed literature; a licensed clinician provides any diagnosis and care.