ADHD and ASD Diagnostic Tests: scientific tools

Duration: 5-8 minutes | Items: 6 key questions | Population: Adults 18+ years

The ASRS was developed by the World Health Organization in collaboration with Harvard University. It is the most widely used adult ADHD screening questionnaire in the world, translated into 35 languages and validated on over 15,000 participants.

The questionnaire covers the 18 symptoms of the DSM-5 grouped into two dimensions: inattention (9 items) and hyperactivity-impulsivity (9 items). The 6 questions of the short version correspond to the most predictive symptoms of the diagnosis according to statistical analyses.

A score of 4/6 or more in the "often/very often" range indicates a high probability of ADHD (sensitivity 68%, specificity 99%). This threshold justifies a specialized consultation for diagnostic confirmation.

Conners-3 Parents: 27 to 110 items depending on the version | Conners-3 Teachers: 39 to 59 items | Conners-3 Self-Report: from 8 years old, 28 to 99 items

The strength of the Conners scales lies in their triangular approach. Symptoms reported by parents, teachers, and the child themselves are compared to identify convergences and divergences. This method allows for distinguishing situational difficulties from persistent disorders.

The scales provide standardized T scores (mean 50, standard deviation 10) for each dimension: inattention, hyperactivity-impulsivity, learning problems, executive function, aggression, peer relationships. A T score ≥ 65 is considered clinically significant.

The CPT measures sustained attention and inhibitory control over 15-20 minutes. The participant must quickly respond to target stimuli (letters, numbers, or specific shapes) while ignoring distractors. This seemingly simple task intensely engages the frontal attentional networks.

Omissions: missed targets (inattention) | Commissions: false alarms (impulsivity) | Mean reaction time: processing speed | Temporal variability: attentional consistency

Over 200 studies validate the use of the CPT in ADHD. Meta-analyses show a moderate to strong effect size (d = 0.5 to 1.2) for differentiating ADHD patients from controls, particularly on reaction time variability.

The Stroop test assesses cognitive inhibition by creating a conflict between an automatic response (reading) and a controlled response (color naming). For example, the word "RED" written in blue requires saying "blue" while inhibiting the automatic reading "red".

The Stroop effect is calculated by the difference between reaction times in incongruent versus congruent conditions. In ADHD, this effect is typically increased, reflecting a difficulty in frontal executive control.

Neuroimaging shows that the Stroop test specifically activates the anterior cingulate cortex and the dorsolateral prefrontal cortex, two key regions of executive functions often impaired in ADHD.

The ADOS-2 is a semi-structured observation protocol that places the participant in standardized social situations to observe their spontaneous responses. The evaluator proposes specific activities (symbolic play, conversation, collaborative tasks) and codes the quality of social interactions in real-time.

Toddler Module: 12-30 months | Module 1: non-verbal or simple phrases | Module 2: phrastic language | Module 3: fluent child/teen language | Module 4: fluent adult language

The ADOS-2 systematically evaluates: reciprocal social communication, the use and understanding of non-verbal communication, repetitive behaviors and restricted interests, the quality of symbolic and imaginative play, atypical sensory responses.

Each item is scored from 0 (typical behavior) to 3 (very atypical behavior). The scores are converted into two domains: Social Affect and Repetitive Behaviors. The total comparison score determines the classification: ASD, autistic spectrum or non-spectrum.

The ADI-R is a semi-structured interview lasting 2 to 3 hours conducted with parents or guardians. It systematically explores the developmental history from birth: first social smiles, language development, symbolic play, peer relationships, repetitive behaviors, reactions to changes.

4-5 years: behaviors at their peak expression | Current Functioning: evolution and adaptation | Early Development: 0-36 months (critical period for diagnosis)

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 direct observation (ADOS) is difficult to perform or uninformative.

The CARS-2 rates 15 behavioral domains on a scale from 1 (normal) to 4 (severely atypical). Each domain corresponds to a key characteristic of autism: social relationships, imitation, emotional response, body use, adaptation to change, visual and auditory response.

Its relative speed (15-30 minutes) and simple structure make it a useful first-level tool. It can be administered from the age of 2 and does not require as extensive training as the ADOS-2.

The CARS-2 is less sensitive to mild profiles (level 1 of the spectrum) and atypical presentations. It serves as a complement but cannot replace the ADOS-2/ADI-R evaluation for a precise differential diagnosis.

Evaluation of ADHD symptoms according to DSM-5 criteria through 18 questions covering inattention, hyperactivity, and impulsivity. Each symptom is assessed for its frequency (never, sometimes, often, very often) and its functional impact in different contexts (work, home, social).

The test generates an overall score and sub-scores by dimension. It indicates the level of probability of ADHD (low, moderate, high) and provides personalized recommendations based on the obtained profile.

Based on an adaptation of the ASRS and Conners scales, validated on a French sample of 2,500 participants. Sensitivity: 82%, Specificity: 76% for clinically confirmed ADHD diagnosis.

Continuous vigilance task adapted from the classic CPT: identification of specific targets (shapes, colors, numbers) among distractors over 12 minutes. Measures sustained attention, impulsivity, and attentional variability.

Omission Rate: missed targets (inattention) | Commission Rate: false alarms (impulsivity) | Mean Reaction Time: processing speed | RT Variability: attentional consistency

The test generates a multidimensional attentional profile with comparison to age norms (percentiles). It identifies specific strengths and weaknesses of the attentional system.

Measures the speed and efficiency of cognitive processing through simple decision tasks (shape matching, visual search, symbolic substitution). Equivalent to the "Processing Speed" subtests of the WAIS-IV.

Processing speed: items/minute | Accuracy: % of correct answers | Efficiency: speed/accuracy ratio | Fatigability: performance evolution over time

Processing speed is one of the most sensitive indicators for ADHD. A score < 10th percentile suggests a neuropsychological consultation, especially if associated with other cognitive difficulties.

Combination of several attentional paradigms (sustained, selective, divided, executive) for a complete attentional profile. Total duration: 25 minutes divided into 6 specialized modules.

Sustained attention: continuous vigilance | Selective attention: filtering distractors | Divided attention: dual task | Flexibility: attentional switching | Inhibition: impulse control | Working memory: maintenance and manipulation

Generation of a detailed report with standardized scores, profile graphs, normative comparisons, and personalized training or consultation recommendations.

Primary care physician: medical history, elimination of differential diagnoses, specialized referral | Cost: 25€ (reimbursed) | Duration: 30-45 min

Psychiatrist/Child psychiatrist: in-depth clinical evaluation, standardized questionnaires | Cost: 50-120€ (partially reimbursed) | Duration: 60-90 min

Neuropsychologist: comprehensive cognitive tests (CPT, Stroop, WISC/WAIS) | Cost: 300-600€ (not reimbursed) | Duration: 3-4h + feedback

Specialist physician: integration of data, differential diagnosis, care plan | Cost: 60-100€ | Duration: 45 min