Diagnostic Tests for ADHD and ASD: Scientific Tools
CPT, Stroop, Conners, ADOS-2, ADI-R — the diagnostic tests for ADHD and autism are numerous and specific. This guide explains the purpose of each tool, how much it costs, and how to start with the free DYNSEO tests before a consultation.
1. Diagnostic Tests for ADHD
The diagnosis of ADHD is based on a multidimensional evaluation that combines subjective questionnaires (what the patient and their surroundings report) and objective cognitive tests (direct measures of attention and executive capabilities). None of these tools taken in isolation is sufficient — it is their combination, interpreted in a complete clinical context, that allows for diagnosis.
ADHD Screening Questionnaires
Adult ADHD Self-Report Scale (6 items, ~5 min)
The ASRS is the most widely used adult ADHD screening questionnaire internationally. It was developed by the World Health Organization and includes 6 questions about symptoms of inattention and hyperactivity/impulsivity in the past 6 months. A high score (4 responses or more in the "often" or "very often" zone) justifies a formal diagnostic consultation. It is available for free online and serves as a useful first filter before any specialized approach.
Conners Rating Scale (27 to 48 items, ~15–20 min)
The Conners scale is the pediatric gold standard for ADHD screening. It exists in three versions: Conners-3 parents (completed by parents), Conners-3 teachers (completed by teachers), and Conners-3 self-assessment (child from 8 years old). The convergence of the three informants is particularly valuable: a child whose parents and teachers report significant symptoms has a much higher diagnostic probability than one whose symptoms appear only in a single context.
Objective Cognitive Tests for ADHD
Continuous Performance Test (15–20 min)
The CPT is the reference cognitive tool for the assessment of ADHD. The child or adult must press a button each time a target stimulus (a specific number or letter) appears and refrain for all others. The test measures four key variables: omissions (missed targets = inattention), commissions (responses to non-targets = impulsivity), mean reaction time (slowed in ADHD), and reaction time variability (higher in ADHD — the patient is sometimes very fast, sometimes very slow, unpredictably).
DYNSEO offers two equivalents accessible for free: the Selective Attention Test (ability to identify targets among distractors) and the Processing Speed Test (reaction time and cognitive efficiency).
Stroop Color-Word Test (5 min)
The Stroop Test measures inhibition — the ability to suppress an automatic response in favor of a controlled response. In its classic version, the patient must name the color of the ink of a color word ("RED" written in blue → respond "blue"). The conflict between the automatism of reading and the requested task generates interference that reveals the quality of frontal executive control.
In ADHD, the interference effect is often more pronounced than in the control population, reflecting the difficulty in inhibiting automatic responses. It is also a test sensitive to prefrontal lesions and cognitive aging.
Comprehensive cognitive assessment (1h30–2h)
The WISC-V (children) and WAIS-IV (adults) are the most commonly used cognitive assessment batteries. In ADHD, the typical profile shows a gap between two indices: Verbal Comprehension (often normal to high, reflecting actual potential) and Processing Speed (often low, reflecting cognitive inefficiency related to inattention). This "sawtooth" profile is revealing and guides the diagnosis.
2. Diagnostic tests for autism spectrum disorder
The diagnosis of autism is more complex than that of ADHD because it does not rely on direct cognitive measures but on the observation and evaluation of behaviors, communication profiles, and developmental histories. The gold standard tools for autism spectrum disorder require specifically trained professionals.
Autism Diagnostic Observation Schedule (45 min)
The ADOS-2 is considered the gold standard for direct assessment of autism. It is a semi-structured observation protocol: the evaluator creates standardized social situations and observes how the patient responds — their way of establishing contact, sharing attention, using spontaneous language, and responding to attempts at interaction. The ADOS-2 includes five modules tailored to the patient's age and language level, from non-verbal to fluent adult.
Its administration requires specific certification and several days of training. It cannot be "taken online." It is the most significant clinical investment in the ASD assessment — and the most informative.
Autism Diagnostic Interview — Revised (2–3h)
The ADI-R is a structured interview conducted with the parents or guardians of a child or adult suspected of autism. It systematically covers the developmental history from birth: language acquisition, early social interactions, repetitive behaviors, sensory peculiarities, early concerns of the parents. The ADI-R is particularly valuable for the retrospective diagnosis of adults (who have no direct memory of their early development) and for cases where the ADOS is difficult to administer.
Childhood Autism Rating Scale (15–30 min)
The CARS-2 is a clinical assessment scale that rates 15 behaviors associated with autism on a scale of 1 to 4, based on direct observation and information obtained from parents. It is used in conjunction with the ADOS-2 and the ADI-R, and can be administered from age 2. Its advantage is its relative speed — but it is less precise for mild profiles (level 1) than the ADOS.
3. ADHD Tests vs Autism Tests: Comparative Table
| Test | Target Disorder | Duration | Estimated Cost | Who Administers It |
|---|---|---|---|---|
| DYNSEO Online Tests | ADHD (screening) | 10–15 min | Free | Self-administration |
| ASRS | Adult ADHD | 5 min | Free | Self-administration |
| Conners | Child ADHD | 15–20 min | Includes assessment | Clinician (parents + teachers) |
| CPT / TOVA | ADHD | 15–21 min | Includes assessment | Neuropsychologist |
| Stroop | ADHD, frontal lesions | 5 min | Includes assessment | Neuropsychologist |
| WISC-V / WAIS-IV | ADHD + Autism (cognitive profile) | 90–120 min | Includes assessment | Psychologist |
| ADOS-2 | Autism (gold standard) | 45 min | Includes autism assessment | Certified ADOS clinician |
| ADI-R | Autism | 2–3h | Includes autism assessment | Trained ADI-R clinician |
| CARS-2 | Autism | 15–30 min | Includes autism assessment | Clinician |
4. Free DYNSEO Tests: Where to Start
Before engaging in a long and costly diagnostic process, DYNSEO online tests provide a first objective indicator of attention capabilities — useful for preparing a medical consultation, having concrete data to bring, or simply better understanding one's cognitive profile.
ADHD Test — Assess your attention
This screening test evaluates ADHD symptoms according to DSM-5 criteria through questions about inattention, hyperactivity, and impulsivity in daily life. It is not medical but serves as an excellent starting point to objectify what one feels. Duration: 10 minutes. Access: free.
Selective Attention Test
Online equivalent of the CPT paradigm: measures the ability to identify targets among distractors, reaction time, and error rate. Provides an objective score comparable to age norms. Duration: 10–12 minutes. Access: free.
Processing Speed Test
Measures the speed and efficiency of cognitive processing — one of the most sensitive indicators of frontal dysfunctions in ADHD. A slowed or highly variable reaction time is a signal to explore with a professional. Access: free.
Concentration and Attention Test
Overall assessment of attentional capacities combining several components (selective, sustained, processing speed). Provides a synthetic attentional profile with comparison to norms. Access: free.
5. Interpret your results and decide on the next steps
✅ Score within the norm
No urgent action needed. If you experience difficulties despite a good score, other factors (anxiety, sleep, stress) may be at play. Consider a consultation if difficulties persist.
🔵 Score slightly below the norm
Cognitive training recommended. Lifestyle adjustments (sleep, exercise). Retest in 4 to 6 weeks after regular training. Consult if difficulties disrupt your daily life.
🟡 Score significantly below the norm
Medical consultation recommended (general practitioner → specialist). Bring your DYNSEO results to the consultation. A comprehensive neuropsychological assessment may be indicated.
🔴 Very low score + daily symptoms
Specialized consultation without delay (child psychiatrist, neuropsychologist). DYNSEO results can expedite care by providing a first objective indicator to the professional.
💡 Prepare for your consultation with DYNSEO tests
Bringing your DYNSEO test results to your first medical consultation is a good practice. It gives the doctor a first objective indicator, allows for a quick orientation of the clinical interview, and reduces the risk that your difficulties are minimized due to lack of objectification. Also note, before the consultation: how long the difficulties have been present, in what contexts they manifest (work, home, social), and if other family members show similar symptoms.
6. When to consult: warning signs
✔ Consult a professional if you observe:
- ADHD: significant attention difficulties for more than 6 months, in at least two life contexts (work AND home), with real functional impact
- ADHD: ASRS score of 4/6 or higher, or low scores on DYNSEO cognitive tests
- Child ASD: absence of pointing or social gestures at 12 months, absence of words at 16 months, loss of acquired language skills, very restricted interests
- Adult ASD: unexplained chronic social difficulties, intense exhaustion after social interactions, rigid rituals or routines, marked sensory hypersensitivities
- Double diagnosis: "paradoxical" profile combining ADHD and autistic symptoms that neither explains alone
🎯 Start with the free DYNSEO tests
Four complementary tests for an initial objective attention profile:
• Non-medical ADHD Test — DSM-5 symptom screening
• Selective Attention Test — online CPT equivalent
• Concentration and Attention Test — overall attention profile
• Processing Speed Test — speed and cognitive efficiency
And for support:
• ADHD Training — child, teenager, adult
• ASD Training — child, institution, adult
FAQ
What tests are used to diagnose ADHD?
The ADHD diagnosis combines the CPT (15-20 min), the Stroop Test, the Conners questionnaires (children) or ASRS (adults), and the WISC/WAIS. DYNSEO offers free equivalents (Selective Attention Test, ADHD Test, Processing Speed Test) for an initial assessment.
What tests are used to diagnose autism?
The gold standard combines the ADOS-2 (direct observation, 45 min) and the ADI-R (parental interview, 2-3h). The CARS-2 is used as a complement. These tests require specifically trained and certified professionals.
How much does an ADHD or ASD diagnostic assessment cost?
Complete ADHD assessment: €400 to €800. Complete ASD assessment: €500 to €1,500. Initial medical consultation: €50 to €150 (reimbursed). DYNSEO tests: completely free.
Are DYNSEO tests reliable?
DYNSEO tests are screening tools built on scientifically validated paradigms. They provide an initial objective indicator — not a medical diagnosis. They help prepare for a consultation with concrete data and objectify difficulties that can sometimes be hard to describe.
At what age can ADHD and autism be diagnosed?
ASD can be diagnosed as early as 2-3 years (M-CHAT for early screening). ADHD is generally diagnosed from age 6. Both diagnoses can be made at any age, including adulthood — many people are only diagnosed in their 30s to 50s.
Can we take an online ASD test?
There is no valid online equivalent of the ADOS-2 or the ADI-R — these tools require direct observation and a clinical interview. Screening questionnaires (like the AQ — Autism Quotient) provide an indication but do not replace formal assessment. For ADHD, DYNSEO cognitive tests are good first-level tools.
Conclusion: the right tools for the right diagnosis
The diagnosis of ADHD and ASD is a structured process that requires the right instruments, the right professionals, and the right context. Neither too quick (a rushed diagnosis can be wrong), nor too long (every year without a diagnosis is a year without appropriate support). DYNSEO tests are the first accessible, free, and immediate step in a process that deserves to go all the way to a complete clinical evaluation when the signals justify it.
Start with DYNSEO screening tests, prepare for your consultation with your results, and access specialized training to better understand and support the concerned profile.