Getting assessed for ADHD involves tools — questionnaires, structured interviews, and in some cases computerised tests. Understanding what each tool actually measures, how accurate it is, and what its limitations are puts you in a better position to interpret results and to ask informed questions during the diagnostic process. No single tool diagnoses ADHD. Every guideline, including NICE NG87 and the APA, specifies that diagnosis requires comprehensive clinical assessment.1 But these tools are part of that process, and knowing what they do matters.
The DSM-5 criteria: what any tool is measuring against
Before examining individual instruments, it helps to understand what they are all referencing. The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) defines ADHD through 18 symptom criteria: 9 for inattention and 9 for hyperactivity-impulsivity.2 For a diagnosis, an adult must meet at least 5 of 9 criteria in one or both domains, with symptoms present before age 12, evident in two or more settings, and causing clinically significant functional impairment.
The ICD-11, used alongside or instead of the DSM-5 in many countries, classifies ADHD as a neurodevelopmental disorder with broadly similar criteria, though it uses the term "hyperkinetic disorder" in some contexts and recognises ADHD as three presentations: predominantly inattentive, predominantly hyperactive-impulsive, and combined.
Every screening and diagnostic tool described below is measuring aspects of these criteria — but they do it differently, with different levels of depth and accuracy.
ASRS: the WHO self-report screener
The Adult ADHD Self-Report Scale (ASRS) was developed by the World Health Organization in collaboration with researchers at Harvard and NYU. It is the most widely used ADHD screening tool in the world, referenced in national and international guidelines, and available free of charge.3
The ASRS exists in several versions. The most commonly used are:
ASRS v1.1 — an 18-item questionnaire covering all DSM-IV symptom criteria. Part A contains 6 items selected as the most predictive of ADHD; Part B contains the remaining 12 items for broader symptom detail. The original dichotomous scoring (screen-positive/negative based on response thresholds) showed sensitivity of 68.7% and specificity of 99.5% in general population validation.3
ASRS-5 — updated to align with DSM-5 criteria, using a 5-point Likert scale (never to very often) rather than dichotomous scoring. This version has demonstrated substantially improved sensitivity. In validation studies, the ASRS-5 achieved sensitivity of 91.4% and specificity of 96.0% in a general population sample, and sensitivity of 91.9% with specificity of 74% in a clinical sample.4 A cutoff score of 14 or above on Part A indicates probable ADHD requiring further assessment.
A 2024 review by Caroline and colleagues in the Journal of Attention Disorders identified approximately 10 adult-focused ADHD rating scales with strong psychometric properties, concluding that the ASRS remains among the most diagnostically accurate, though noting that fewer scales directly quantify functional impairment — which is essential because a diagnosis requires proof that symptoms disrupt daily life.5
What the ASRS tells you: Whether your self-reported symptom pattern is consistent with ADHD at a level that warrants clinical investigation. It is a screener, not a diagnostic instrument. A positive ASRS result means "investigate further." A negative result, particularly on the older v1.1, does not rule out ADHD — roughly 1 in 3 adults with ADHD may screen negative on the v1.1 due to its lower sensitivity.
What the ASRS does not tell you: Whether your symptoms are caused by ADHD specifically (as opposed to anxiety, depression, sleep disorders, or other conditions that can produce overlapping symptoms), whether you meet the functional impairment criterion, or whether symptoms were present in childhood.
DIVA-5: the clinician-administered diagnostic interview
The Diagnostic Interview for ADHD in Adults, version 5 (DIVA-5) is a structured clinician-administered interview developed by Sandra Kooij and colleagues at the DIVA Foundation. It is specifically designed for comprehensive ADHD diagnosis in adults and is the most widely used structured diagnostic interview for this purpose globally.6
The DIVA-5 evaluates all 18 DSM-5 symptom criteria across two time periods: childhood (before age 12) and adulthood. For each symptom, the interview provides concrete, real-life examples of how that symptom typically manifests — drawing from clinical observations and patient accounts — to help both clinician and patient identify whether the criterion is met. This is particularly valuable because many adults with ADHD have normalised their difficulties and may not initially recognise a symptom description as applying to them.6
The interview then assesses functional impairment across five domains: education, work, social relationships, leisure activities, and family or partner relationships. This is critical: the DSM-5 requires evidence that symptoms cause clinically significant impairment, not just that they exist.
The DIVA-5 has been translated into more than 25 languages. Formal validation studies have been completed for the Korean version (diagnostic accuracy 92%, sensitivity 91.30%, specificity 93.62%), the Farsi version, and most recently the Italian version (2025), which demonstrated good internal consistency (Cronbach's alpha 0.61–0.78) and concurrent validity with the ASRS and BAARS-IV scales.7 8
What the DIVA-5 tells you: Whether you meet full DSM-5 diagnostic criteria for ADHD, including childhood onset, symptom pervasiveness, and functional impairment. It provides a structured, evidence-based pathway to a formal diagnosis.
What the DIVA-5 does not tell you: The DIVA-5 relies on retrospective self-report and informant report for childhood symptoms. Memory is imperfect, and childhood symptoms may be difficult to verify in adults who lack access to school records or family members who can corroborate. The DIVA-5 is also only as good as the clinician administering it — training and experience in ADHD assessment matter.
QbTest: objective measurement of attention, impulsivity, and activity
The QbTest (Quantified Behavior Test) represents a fundamentally different approach. Developed by Qbtech, it is a computerised continuous performance test (CPT) combined with infrared motion tracking. The person performs a 15–20 minute sustained attention task (responding to target stimuli and withholding responses to non-targets) while a head-mounted reflector tracks physical movement.9
The test produces objective, quantitative data on three ADHD symptom domains: inattention (measured by omission errors and reaction time variability), impulsivity (measured by commission errors), and hyperactivity (measured by distance, area, and microevents of head movement). Results are compared against age- and sex-matched normative data and presented as a visual report.
In 2024, NICE issued diagnostics guidance (DG60) recommending QbTest alongside standard clinical assessment for 6–17 year-olds — making it the first digital technology formally recommended by NICE for ADHD assessment.9 10 The NHS FOCUS ADHD programme has integrated QbTest across 15 Health Innovation Networks in England, with reported savings of 95,097 hours of healthcare capacity and 1,582 clinical appointments.9
A systematic review and meta-analysis by Bellato and colleagues (2024) in the Journal of Child Psychology and Psychiatry examined the clinical utility of QbTest. A comprehensive review of ten studies determined pooled sensitivity of 0.84 and specificity of 0.84. A composite measure based on all three domains yielded 86% sensitivity and 83% specificity in one study.10 A 2025 review in Frontiers in Psychiatry, covering studies from 2014 to 2025, reported pooled sensitivity of 0.78 and specificity of 0.70 across five studies.11
QbTest has also demonstrated significant utility in medication management: it can detect stimulant treatment effects within hours of dose administration and can identify symptom-level changes across dose levels — including cases where subjective rating scales did not detect improvement.9 10
What the QbTest tells you: How your attention, impulsivity, and physical activity compare to objective norms during a controlled task. It provides data that is not influenced by subjective reporting bias.
What the QbTest does not tell you: Whether you have ADHD. The test is not condition-specific — anxiety, autism spectrum conditions, sleep deprivation, and unfamiliarity with computerised tasks can all degrade specificity. QbTest performance in a 15-minute controlled test does not necessarily reflect real-world functioning. It is an adjunct to clinical assessment, not a replacement for it.
Other screening tools worth knowing about
CAARS (Conners' Adult ADHD Rating Scales) — a well-validated self-report and observer-report measure that assesses ADHD symptoms and related problems in adults. Available in long (66 items) and short (26 items) forms. Strong psychometric properties and widely used in research and clinical practice.
BAARS-IV (Barkley Adult ADHD Rating Scale-IV) — based on Russell Barkley's model, this scale assesses current and childhood symptoms aligned with DSM-5 criteria. It uniquely includes a functional impairment section, addressing the gap identified in the 2024 Caroline et al. review.5
WURS-25 (Wender Utah Rating Scale) — a 25-item retrospective scale assessing childhood ADHD symptoms. Useful when the question is whether symptoms were present before age 12, but relies on adult recall of childhood experiences, which introduces recall bias.
Brown EF/A Scales — as discussed in our article on executive function, these scales assess the six clusters of executive function impairment that characterise ADHD. They capture impairments (activation, focus, effort, emotion, memory, action) that standard symptom checklists may miss.
What a comprehensive assessment looks like
No screening tool, no matter how well-validated, constitutes a diagnosis on its own. A comprehensive ADHD assessment typically includes:
A detailed clinical history — developmental history, educational history, occupational history, and relationship patterns across the lifespan. The assessor is looking for a chronic, pervasive pattern, not recent-onset difficulties.
A diagnostic interview — either a structured instrument like the DIVA-5 or a thorough clinical interview covering DSM-5 criteria, childhood onset, and functional impairment across multiple settings.
Self-report rating scales — typically the ASRS-5 and/or CAARS/BAARS-IV.
Collateral information — ideally from someone who knew the person in childhood (a parent, sibling, or family member) and/or school reports. NICE NG87 recommends informant-corroborated assessment but acknowledges this is not always possible.1
Assessment for differential diagnosis and comorbidity — anxiety, depression, bipolar disorder, autism spectrum conditions, sleep disorders, thyroid dysfunction, and substance use can all produce symptoms that overlap with ADHD. A competent assessment considers and either rules out or identifies these as co-occurring conditions.
Optional objective testing — QbTest or other CPT measures, used to supplement clinical judgment and increase diagnostic confidence.
Understanding sensitivity and specificity
When you see statements like "the ASRS-5 has 91.4% sensitivity and 96% specificity," here is what those numbers mean in practical terms:
Sensitivity is the proportion of people who actually have ADHD who are correctly identified by the test. A sensitivity of 91.4% means that 91 out of 100 people with ADHD will screen positive. The remaining 9 will be missed (false negatives).
Specificity is the proportion of people who do not have ADHD who are correctly identified as not having it. A specificity of 96% means that 96 out of 100 people without ADHD will screen negative. The remaining 4 will incorrectly screen positive (false positives).
No test achieves 100% in both. Screening tools are designed to be sensitive — to catch as many true cases as possible, accepting some false positives — while diagnostic tools aim for higher specificity to confirm the diagnosis accurately. This is why the clinical pathway moves from screening (high sensitivity) to comprehensive assessment (high specificity).
If you have completed a screening tool and scored above the threshold, this is the beginning of the diagnostic process, not the end. If you scored below the threshold but strongly suspect ADHD, the screening result does not close the door — particularly if you completed the older ASRS v1.1, which has lower sensitivity, or if you are a woman, since many screening tools were originally validated on predominantly male samples.
