Key Takeaways
- Whether ADHD medication is working is judged mainly by your daily life, symptom ratings and side effects; a cognitive test is at most one extra data point.
- On average, stimulant medication improves performance on attention and memory tasks, but the effect in adults is small and varies a lot between people.
- Some clinicians repeat cognitive tasks before and after a medication change, but no published study shows that Creyos can guide ADHD dose decisions.
- Scores move for many reasons besides medication: practice, sleep, mood, timing of the dose and the testing setup.
A cognitive test can add a useful number to the question “is my ADHD medication working?”, but it cannot answer it alone. Research shows that stimulant medication improves task performance on average, yet the gain in adults is small and differs widely from person to person. Some clinicians compare a baseline test with a repeat test after starting or adjusting medication. That is a clinical practice, not a proven method: no peer-reviewed study shows that Creyos results can guide ADHD medication decisions. Here is how the comparison works and where it can mislead.
What “working” means for ADHD medication
What Creyos can and can’t do
It can
- Measure attention, working memory, planning and response inhibition against people your age
- Give a before-and-after comparison your clinician may read alongside other information
- Flag a change in a task score that is larger than expected from chance (a lenient statistical flag)
It can’t
- Show on its own whether a medication or dose is right for you
- Diagnose ADHD (Creyos’s own guide calls its ADHD protocol “not a standalone diagnostic tool”)
- Stand in for how you are doing at work, school and home
ADHD treatment has practical goals: finishing work without heroic last-minute effort, following conversations, driving safely, keeping track of appointments, feeling less scattered. A medication “works” when those things improve, side effects are tolerable, and sleep and appetite stay reasonable.
That is why the core of monitoring is still conversation and structured ratings. If you want the general method for tracking any psychiatric medication, with questionnaires, side-effect notes and visit summaries, see how to tell whether your psychiatric medication is working. This page is about one narrower question: what cognitive tasks can add for ADHD.
What research shows about stimulants and test scores
Stimulant medication does change performance on cognitive tasks, on average. Two meta-analyses on one of the most widely used stimulants give a sense of scale:
- Adults: Pievsky and McGrath (2018) pooled 21 double-blind trials lasting about 18 days on average. Scores on neurocognitive and driving tests were higher on medication than on placebo, but the overall effect was small (g = 0.17), with gains in working memory, vigilance and steadier reaction times.
- Children and teens: Coghill and colleagues (2014) analyzed 36 placebo-controlled studies in ages 5–18. Medication beat placebo on memory, reaction time, reaction-time variability and response inhibition.
Coghill’s team added an important caution: the link between cognitive test deficits and the everyday symptoms of ADHD “seems more complex than originally thought.” A person can feel and function much better with little change on a test, or show a clear test gain without feeling different. A small average effect also means that, for any one person, a retest difference may be lost in normal day-to-day variation.
How a before-and-after comparison works
When clinicians use cognitive tasks this way, the logic is simple: take a baseline, change one thing, retest under the same conditions, and see whether the difference is bigger than chance. In practice that means:
- A baseline before starting medication, or before a planned change.
- The same tasks at the repeat test. Creyos’s ADHD protocol uses four core tasks (Spatial Planning, Token Search, Feature Match and Double Trouble) plus the SART, a sustained-attention task, and produces 14 markers.
- Matched conditions: similar time of day, the same device type (a computer or a tablet 8 inches or larger; phones are not recommended), a quiet room, a normal night’s sleep.
- A planned gap long enough for the change to settle. How long your clinician waits between tests is something to ask our team about.
- Reading the result in context, together with symptom ratings, side effects and what you notice day to day.
Creyos reports include a Meaningful Change Indicator, which flags differences unlikely to be chance. Its threshold is lenient (p < 0.2), so it is designed to catch possible changes rather than to confirm them. For the mechanics of retesting, see retesting with Creyos; for the protocol itself, the Creyos ADHD assessment. The Creyos cognitive assessment guide covers the basics.
Why scores move for reasons other than medication
This is the part most marketing leaves out. A retest score reflects everything about that day, not just the medicine:
| Factor | What it does to a repeat score |
|---|---|
| Practice | Creyos scores are normed to a person’s first attempt. In Creyos’s own data, second attempts were about 3% better on average, and close to 8% on one task (Polygons), with no medication involved. |
| Test-retest reliability | The average correlation between first and second attempts was r = 0.69, ranging from 0.45 (Paired Associates) to 0.92 (Double Trouble). Several tasks fall below the level usually wanted for decisions about one person. |
| Sleep | A large online study using these tasks found that people who usually slept about four hours a night scored as if roughly eight years older on overall cognition. |
| Mood and anxiety | Low mood slows processing; worry pulls attention. Both can mask or mimic a medication effect. |
| Dose timing | A test taken when a dose is at full effect differs from one taken as it wears off. Your clinician will tell you whether to take your usual medication that morning. |
| Setting | Interruptions, a different device or a noisy room add noise to timed tasks. |
None of this makes testing useless. It means one retest is a hint, not a verdict, and it should never be the only reason a dose goes up or down.
Pairing tasks with ratings and real life
Task scores make the most sense next to symptom ratings. For adults, Creyos’s ADHD protocol includes the six-question screener from the Adult ADHD Self-Report Scale (ASRS v1.1 Part A), which asks how often common attention and restlessness symptoms have shown up over the past six months. Our guide to the ASRS adult ADHD self-report scale explains it. For younger patients, the protocol pairs the tasks with parent forms: the Vanderbilt scale for ages 6–11 and the SWAN for ages 12–17.
Add a few real-world markers you care about, written down before the change: “emails answered the same day,” “no missed appointments this month,” “homework started without three reminders.” A partner, parent or coworker who sees you daily can rate these too. When task scores, ratings and real-life markers agree, you can trust the picture more. When they disagree, the disagreement itself is worth discussing.
When medication seems to stop working
If a medication that helped seems weaker, the cause is often outside the pill: shorter sleep, more stress, hormonal shifts, illness, or changes in diet and routine. Our articles on why ADHD medication stops working and natural factors that affect ADHD medication walk through these.
A repeat cognitive test can sometimes help separate “my attention really is worse” from “I’m exhausted and stressed,” but only if the testing conditions are comparable. Do not raise, lower or skip doses on your own to see what happens. Changes to a controlled medication need your prescriber.
Contact your prescriber promptly if…
Who prescribes, and what to ask before a repeat test
At Willow & Stone, Dr. Stacey Forbes, DNP, APRN, PMHNP-BC, leads ADHD evaluation and ongoing care. In Texas, stimulant medications are Schedule II drugs, and they are prescribed by the collaborating physician who works with Dr. Forbes, because Texas law limits nurse practitioners’ Schedule II prescribing. Our guide to ADHD medication and telehealth rules explains the state differences.
Before any repeat test, it helps to ask:
- What question is this retest meant to answer?
- Should I take my usual medication that morning, and at what time relative to the test?
- Will I use the same device and setting as last time?
- How will you weigh the result against my ratings and how I am doing?
- What does it cost, and is it done at home or in the office? These are confirmed when you book; ask our team.
Follow-up visits are $150; see pricing.
Common Questions
Does ADHD medication improve memory?
On average, stimulant medication modestly improves working memory and attention on lab tasks. In adults the pooled effect across trials was small. Many people notice the benefit more as being able to start and finish things than as better memory. Individual responses vary widely.
Can Creyos tell me if my ADHD dose is right?
No. There is no published evidence that Creyos results can guide ADHD medication dosing. A clinician may repeat the tasks to compare with your baseline, but practice effects, sleep, mood and dose timing all affect scores. Dose decisions rest on symptoms, function and side effects, discussed with your prescriber.
Should I take my ADHD medication before a cognitive test?
It depends on what the test is for. A baseline is sometimes taken before medication starts, while a follow-up may be timed to when a dose is active. Your clinician will tell you whether to take your usual medication that morning. Don’t change your dose on your own for a test.
How soon after a medication change should I retest?
There is no standard interval, and Creyos has not published one for medication changes. Clinicians usually wait until the change has settled and conditions can be matched. Ask our team what interval your clinician uses.
Will my score go up just because I have taken the test before?
Often, a little. In Creyos’s own data, second attempts averaged about 3% higher, more on some tasks. Scores are normed to first attempts, so a modest rise on retest is expected and is not proof of a medication effect.
If my test scores are normal, does that mean I don’t need ADHD treatment?
No. Creyos’s guidance says a person with ADHD may score in the typical range on many or most markers. ADHD is diagnosed and treated based on a full clinical picture, not a test score.
Part of our Creyos cognitive assessment guide
Sources & Further Reading
- Creyos — Science Overview (PDF; test-retest reliability and learning effects, p.12)
- Creyos — ADHD Report Science Guide (PDF)
- Creyos — Report Interpretation Guide (PDF)
- Pievsky & McGrath 2018 — Neurocognitive effects of methylphenidate in adults with ADHD: a meta-analysis
- Coghill et al. 2014 — Effects of methylphenidate on cognitive functions in children and adolescents with ADHD (Biol Psychiatry)
- Wild et al. 2018 — Dissociable effects of self-reported daily sleep duration on high-level cognitive abilities (Sleep)
This article is general education, not a diagnosis or advice for your situation. Creyos results support, and never replace, a clinical evaluation; only a clinician who has evaluated you can diagnose a condition or recommend treatment. Do not start, stop, or change a medication without talking to the clinician who prescribes it.
If you need help right now
Willow & Stone is an outpatient practice and is not an emergency service. If you or someone you care about is in immediate danger, call 911.
For urgent mental health support at any hour, call or text 988 to reach the Suicide & Crisis Lifeline, or text HOME to 741741 for the Crisis Text Line. Both are free, confidential, and available 24/7 nationwide.
Dr. Stacey Forbes, DNP, APRN, PMHNP-BC
Board-certified Psychiatric-Mental Health Nurse Practitioner and founder of Willow & Stone Integrative Mental Health. Nearly two decades of clinical experience; integrative, root-cause psychiatry in person in Arlington and by telehealth. Licensed in Texas, New Mexico, Florida, Alaska, Arizona, Colorado & Washington.
About Dr. Forbes →