CPT testing is an aid to clinical judgement, not a replacement for it. The DSM-5-TR diagnostic process for ADHD relies on clinical interview, history, multiple-source rating scales, and functional impairment — none of which a CPT alone can replace. But CPT does add information that interview and rating scales don't capture, and clinicians who use it routinely report several specific use-cases where it changes management.
Where CPT adds value
1. Disambiguating presentations with confounding factors
When a patient's symptoms could fit ADHD, anxiety, depression, sleep disorder, or some combination, CPT can provide a measurement that interview alone can't. Specifically: high RT variability with normal mean performance is highly characteristic of ADHD and is not a typical anxiety, depression, or sleep-deprivation pattern. A patient with subjective attention complaints whose CPT shows normal performance — including normal RTV — is more likely to have a non-ADHD attention problem.
2. Quantitative outcome measure for titration
Subjective titration relies on patient self-report, rating scale change, and functional outcomes. CPT provides a quantitative measure that can be tracked across visits at consistent time-of-day. Within-subject change pre-/post-medication is often more meaningful than absolute percentile values: a 30% RTV reduction on medication is a strong response signal regardless of where the patient sits on population norms.
3. Higher-functioning adults with subtle presentations
Adults with intelligence and compensation strategies can perform well on rating scales and present articulately in interview while still having significant ADHD-related attention dysfunction. CPT performance is harder to compensate for — particularly RTV, which captures lapsing rather than capability.
4. Establishing a baseline before treatment
Even when CPT isn't planned for routine follow-up, a baseline before starting treatment provides an objective comparator if response becomes ambiguous later. "We saw a 40% reduction in commission errors at 8 weeks on Vyvanse 50 mg" is a quantitatively defensible response statement.
5. Patient communication and engagement
A percentile chart with the patient's pre-treatment scores plotted against population norms can be a powerful communication tool — both for explaining the diagnosis and for showing treatment response. Some clinicians report this is one of the highest-value uses, independent of any quantitative diagnostic addition.
Where CPT doesn't add value
- Rule-in diagnosis on its own. A "positive" CPT alone does not establish ADHD. Many non-ADHD conditions (sleep, anxiety, depression, head injury, certain medications) elevate CPT scores.
- Rule-out on its own. A "negative" CPT alone does not rule out ADHD — particularly in higher-functioning patients with strong compensatory strategies, time-of-day favorable to alertness, or task-novelty-driven engagement.
- Replacing developmental history. The childhood-onset criterion can only come from history, not testing.
- Distinguishing ADHD subtypes definitively. Error patterns are suggestive but not diagnostic of presentation type.
Common workflow patterns
Workflow A: baseline + post-titration
CPT at intake (medication-off if not yet started); repeat at 8–12 weeks once on stable dose. Compare within-subject change. This is the highest-yield, lowest-effort workflow.
Workflow B: at-intake screening
CPT routinely at first ADHD assessment for adults; results integrated alongside interview, ASRS/Conners, and history. Useful for clinicians who want a baseline regardless of titration plans.
Workflow C: titration-driven only
CPT only at decision points — when raising/lowering dose isn't producing expected subjective response, or when patient is uncertain. Lower volume, more targeted.
Workflow D: longitudinal annual
For patients on long-term treatment, an annual CPT to verify continued objective benefit. Particularly useful for patients in long-term stimulant therapy where periodic re-evaluation is appropriate.
Operational considerations
- In-clinic vs. remote administration. In-clinic offers standardization but requires equipment and protected time. Remote (e.g., QbCheck, AxonCPT) offers flexibility but adds environmental variability. The trade-off depends on practice volume and patient population.
- Time-of-day standardization. If using CPT for longitudinal tracking, schedule consistently — morning vs. afternoon performance differs, particularly with stimulants.
- Medication state. Document whether each test is medication-on or medication-off. Both are useful but answer different questions.
- Sleep & engagement check. Brief pre-test sleep / engagement questionnaire helps interpret poor performance.
Communicating results to patients
Three patterns work well:
- Frame as a measurement, not a diagnosis. "This is one piece of data alongside our conversation. Your scores show X, which fits the picture from your history."
- Use the percentile graph. Visual representation lands more reliably than verbal descriptions of metrics.
- Show the change, not just the level. Pre-/post-treatment comparison is the most clinically meaningful output for patients.
What it isn't
CPT is not a brain scan. It doesn't measure dopamine, doesn't visualize structure, doesn't tell you whether a patient "really has" ADHD in some deeper sense. It measures performance on a specific cognitive task. That measurement, combined with everything else you do clinically, can make the assessment and titration process more grounded — but only as one input among many.
Compare available CPT tools in the comparison table or use the score calculator to ballpark percentile values from raw scores.