Understanding the science, structure and clinical reasoning behind a comprehensive Adult ADHD assessment
By Dr. Emmanuel Eni Amadi, PhD, MBA
Adult ADHD Clinician | GPhC Registered Pharmacist Independent Prescriber (GPhC Reg. No: 20-65-651) | UKAAN-Trained | Medical Scientist
Published: Sunday, 25 October 2026
Introduction: A Diagnosis Should Explain a Life, Not Simply Label It
Imagine a 38-year-old professional who has spent much of their working life struggling with missed deadlines, forgetfulness, poor organisation and difficulty completing tasks.
Despite being intelligent, educated and professionally capable, they repeatedly experience difficulties managing responsibilities that others appear to handle effortlessly.
Eventually, they complete an online ADHD questionnaire.
The result suggests that they may have Adult ADHD.
But what happens next?
How does a clinician determine whether these difficulties genuinely represent Attention Deficit Hyperactivity Disorder rather than anxiety, depression, chronic sleep deprivation or another medical or psychological condition?
This is where comprehensive clinical assessment becomes essential.
Two important components of contemporary Adult ADHD assessment are the Diagnostic Interview for ADHD in Adults, Fifth Edition (DIVA-5) and the diagnostic criteria contained in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).
However, neither should be misunderstood as a shortcut to diagnosis.
A reliable diagnosis requires something more fundamental: an appropriately qualified clinician who can interpret evidence, investigate alternative explanations and formulate a defensible clinical conclusion.
As NICE (2018, updated 2025) emphasises, ADHD diagnosis requires comprehensive clinical assessment rather than reliance on questionnaires or rating scales alone.
1. Understanding DSM-5: The Diagnostic Framework
The DSM-5, published by the American Psychiatric Association in 2013 and subsequently updated through the DSM-5-TR in 2022, provides internationally recognised diagnostic criteria for ADHD.
The diagnostic framework identifies two principal symptom domains: inattention and hyperactivity–impulsivity.
In adults, inattention may manifest through difficulties sustaining concentration, organising activities, following instructions, completing tasks, remembering appointments or managing competing responsibilities.
Hyperactivity and impulsivity may present as internal restlessness, excessive talking, difficulty waiting, interrupting others or acting before considering consequences.
Importantly, adult hyperactivity does not always resemble the overt physical activity commonly associated with childhood ADHD.
For individuals aged 17 years and older, DSM-5 requires at least five qualifying symptoms within either the inattentive or hyperactive–impulsive domain.
These symptoms must have persisted for at least six months, with several symptoms present before the age of 12.
They must also occur in at least two settings, interfere with or reduce the quality of functioning, and not be better explained by another mental disorder (American Psychiatric Association, 2022).
The essential point is that experiencing ADHD-like symptoms is not, by itself, sufficient to establish ADHD.
The clinician must investigate their persistence, developmental origins, clinical significance and relationship to other conditions.
2. What Is DIVA-5?
DIVA-5 is a semi-structured diagnostic interview developed specifically to support the assessment of ADHD in adults.
It is based on DSM-5 criteria and systematically examines ADHD symptoms during both childhood and adulthood.
Unlike a brief screening questionnaire, DIVA-5 encourages the clinician to explore real-life examples of symptoms and their consequences.
The interview addresses the 18 core DSM-5 ADHD symptoms: nine relating to inattention and nine relating to hyperactivity–impulsivity.
It also examines the developmental history of these difficulties and their impact on everyday functioning.
According to the DIVA Foundation (n.d.), the instrument was designed to support a structured exploration of symptoms, their persistence and associated impairment.
This structure helps clinicians move beyond simple yes-or-no responses.
For example, a patient may report difficulty organising tasks.
Rather than accepting this statement without further exploration, the clinician may investigate how the difficulty manifests in employment, household management, financial responsibilities and relationships.
The clinician must also establish whether similar difficulties existed during childhood.
DIVA-5 provides structure. Clinical expertise provides interpretation. DIVA Foundation
3. How a Comprehensive DIVA-5 Assessment Works
A comprehensive assessment should begin with the person's presenting concerns.
Why are they seeking assessment now?
What difficulties have they experienced?
How have these difficulties affected their education, employment, relationships and daily functioning?
The clinician then explores the recognised ADHD symptom domains.
Exploring inattention
A patient may describe frequently losing important documents, forgetting appointments or struggling to complete administrative tasks.
The clinician should seek specific examples.
For instance, difficulty completing work may arise from distractibility, poor task organisation or problems sustaining attention.
However, similar difficulties may also occur during depressive episodes, severe anxiety or prolonged sleep deprivation.
The clinician must therefore examine the wider context.
Exploring hyperactivity and impulsivity
In adults, hyperactivity may be experienced as persistent internal restlessness rather than obvious physical overactivity.
An individual may find it difficult to relax, remain mentally occupied with several activities simultaneously or feel uncomfortable during prolonged periods of inactivity.
Impulsivity may affect conversations, purchasing decisions, interpersonal relationships or responses to stressful situations.
The purpose is not merely to identify behaviours but to establish whether they form part of a persistent neurodevelopmental pattern.
Establishing functional impairment
An adult may demonstrate several ADHD symptoms while maintaining a successful career.
Does this automatically exclude ADHD?
No.
Some individuals develop compensatory strategies that conceal the extent of their difficulties.
They may achieve professional success through excessive working hours, rigid routines or substantial support from others.
The Royal College of Psychiatrists (2023) recognises that apparent achievement should not automatically exclude clinically significant impairment.
The assessment should therefore examine not only what someone achieves but also the difficulties and consequences associated with achieving it. www.rcpsych.ac.uk
4. Why Childhood History Is Essential
ADHD is classified as a neurodevelopmental disorder.
Consequently, establishing evidence of childhood symptoms is a fundamental part of adult diagnosis.
The DSM-5 framework requires several relevant symptoms to have been present before age 12.
However, many adults seeking their first assessment have never previously received an ADHD diagnosis.
Some may have performed well academically.
Others may have benefited from highly structured family environments or considerable parental support.
These circumstances can make childhood symptoms less obvious.
A comprehensive assessment therefore explores school experiences, attention, behaviour, organisation, relationships and developmental history.
Where available and appropriate, supporting evidence may include school reports, historical clinical records or information from someone who knew the individual during childhood.
Such information should be obtained with appropriate consent.
Importantly, the absence of school reports or an available childhood informant does not automatically invalidate an assessment.
The Royal College of Psychiatrists (2023) advises that an inability to obtain corroborative history for reasons outside the patient's control should not necessarily exclude diagnosis when the wider clinical evidence is sufficient.
The clinician must document what evidence was available, what was missing and how any uncertainty affected the diagnostic conclusion.
5. Can DIVA-5 Reliably Identify Adult ADHD?
Research supports the clinical usefulness of structured diagnostic interviews.
Hong et al. (2020) evaluated the Korean version of DIVA-5 in a study involving 279 participants recruited from psychiatric outpatient clinics.
The researchers reported diagnostic accuracy of 92%, sensitivity of 91.3% and specificity of 93.6% when comparing DIVA-5 findings with specialist clinical diagnoses.
These findings provide encouraging evidence for the instrument's validity in the population studied.
However, they should not be interpreted as demonstrating identical performance across every clinical population, language or healthcare setting.
More importantly, a validated interview does not eliminate the need for clinical judgement.
The UK Adult ADHD Network's Adult ADHD Assessment Quality Assurance Standard (AQAS) emphasises that diagnostic assessment should involve open questioning, detailed clinical exploration and consideration of alternative diagnoses (Adamou et al., 2024).
The purpose of a structured interview is to improve the quality of evidence—not to replace the clinician responsible for interpreting it. PubMed
6. The Diagnostic Challenge: ADHD or Something Else?
One of the most important responsibilities in Adult ADHD assessment is “differential diagnosis” - what I term “the DD”.
Several conditions may produce symptoms resembling ADHD.
Depression can impair concentration, motivation and memory.
Anxiety may produce restlessness, distractibility and difficulty completing tasks.
Bipolar disorder can involve increased activity, impulsivity and changes in concentration, particularly during mood episodes.
Sleep disorders may produce daytime fatigue, impaired attention and executive functioning difficulties.
Other relevant considerations include substance use, trauma-related conditions, autism and physical health problems.
These conditions are not always alternatives to ADHD.
Some may coexist with it.
For example, an adult may have longstanding ADHD alongside a more recently developed depressive disorder.
The clinician must determine whether ADHD diagnostic criteria are independently satisfied and how coexisting conditions contribute to the person's difficulties.
This requires a comprehensive psychiatric, developmental, medical and psychosocial assessment.
The UKAAN AQAS specifically cautions against assessments that rely excessively on closed questions or symptom checklists because they risk overlooking alternative explanations (Adamou et al., 2024).
A positive DIVA-5 symptom profile must therefore be interpreted within the broader clinical picture.
7. A Practical Clinical Illustration
Consider a hypothetical patient, Sarah, aged 36.
Sarah works in financial services and has recently experienced increasing difficulties managing deadlines, organising appointments and completing administrative responsibilities.
She reports feeling overwhelmed and frequently distracted.
An initial ADHD screening questionnaire suggests clinically relevant symptoms.
During a structured diagnostic interview, Sarah describes longstanding difficulties with organisation, forgetfulness and sustaining attention.
Further developmental questioning identifies similar difficulties during childhood.
With Sarah's consent, information from a family member provides additional historical context.
However, the clinician also discovers that Sarah has recently developed significant anxiety and disrupted sleep.
A comprehensive assessment must therefore consider two possibilities.
First, Sarah may have longstanding ADHD, with anxiety and sleep disturbance contributing additional impairment.
Alternatively, some of her current difficulties may be better explained by another condition.
The clinician should not assume either conclusion.
The appropriate outcome depends on the complete clinical evidence, the recognised diagnostic criteria and the clinician's formulation.
This hypothetical example illustrates why a diagnostic interview is only one component of comprehensive assessment.
8. Who Is Qualified to Diagnose Adult ADHD?
NICE NG87 states that ADHD should be diagnosed only by a specialist psychiatrist, paediatrician or another appropriately qualified healthcare professional with training and expertise in diagnosing ADHD.
This distinction is important.
Professional registration, independent prescribing authority and completion of ADHD training are relevant qualifications, but they do not automatically establish independent diagnostic competence.
The clinician must have the necessary knowledge, practical experience and competence to undertake the assessment safely.
Appropriate supervision, clinical governance and multidisciplinary support are particularly important when developing specialist diagnostic practice.
The UKAAN AQAS similarly emphasises assessor competence, clinical interviewing skills and access to appropriate supervision (Adamou et al., 2024).
For patients, the key question is not simply whether a clinician can administer DIVA-5.
It is whether the clinician is appropriately qualified and competent to evaluate the complete diagnostic picture.
9. What Happens After the Diagnostic Interview?
A comprehensive assessment should produce a clear clinical formulation.
The clinician must establish whether the diagnostic criteria are met, whether another explanation is more appropriate or whether further information is required.
The conclusion should be supported by documented evidence.
Where ADHD is diagnosed, the clinician should explain the relevant presentation, functional consequences, coexisting conditions and available management options.
Where the evidence is insufficient, the clinician should explain the uncertainty and identify appropriate next steps.
A diagnosis should never be forced simply because the patient has waited a long time for assessment.
Equally, genuine ADHD should not be dismissed because the individual appears academically successful, professionally accomplished or outwardly organised.
The objective is diagnostic accuracy, supported by clinical reasoning and compassionate communication.
10. Why Diagnostic Quality Matters to Healthcare Leadership
The increasing demand for Adult ADHD services presents an important challenge for healthcare organisations.
Improving access is essential.
However, expanding assessment capacity without maintaining appropriate clinical standards risks creating further problems.
Poorly documented or inadequately supported diagnoses may lead to repeated assessments, uncertainty about treatment and difficulties coordinating care.
High-quality services therefore require more than appointment availability.
They need competent clinicians, structured assessment pathways, appropriate supervision, reliable documentation and effective clinical governance.
The UKAAN AQAS was developed partly to improve the consistency and quality of Adult ADHD assessments and reports (Adamou et al., 2024).
From a healthcare leadership perspective, diagnostic quality and operational efficiency should not be treated as competing objectives.
A sustainable ADHD service must deliver timely access without compromising clinical accuracy, patient safety or professional accountability.
My Professional Perspective
My interest in Adult ADHD builds upon more than two decades of experience across clinical pharmacy, pharmaceutical leadership, medical science and healthcare governance.
As a GPhC-registered Pharmacist Independent Prescriber, I have undertaken specialist UKAAN and Harley Mental Health trainings in Adult, Children, and Young People with ADHD, assessment, diagnosis and pharmacological treatment.
My clinical development has also included supervised exposure to ADHD screening, structured assessment processes, medication reviews and monitoring within primary care.
This supervised experience has strengthened my understanding of the clinical reasoning and multidisciplinary collaboration required in Adult ADHD care.
My continuing professional objective is to contribute to safe, evidence-based ADHD services while developing further specialist competence within appropriate clinical governance and supervision arrangements.
Conclusion: The Diagnosis Is More Than the Interview
DIVA-5 is an important instrument.
DSM-5 provides a recognised diagnostic framework.
Together, they help clinicians systematically investigate the symptoms and developmental history associated with Adult ADHD.
But neither replaces a comprehensive clinical assessment.
A reliable diagnosis requires the clinician to examine symptoms, childhood history, functional impairment, coexisting conditions and alternative explanations.
The result should be a defensible clinical formulation—not merely a completed questionnaire.
For patients, the goal is understanding.
For clinicians, the responsibility is accuracy.
For healthcare organisations, the priority must be maintaining clinical quality while improving access to appropriate care.
A good ADHD assessment does not simply ask whether someone has symptoms. It asks whether the complete evidence supports the diagnosis.
That distinction matters.
And so does the person behind the diagnosis.
About the Author
Dr. Emmanuel Eni Amadi, PhD, MBA
ADHD Clinician | Adult, Children & Younge People with ADHD | GPhC Registered Pharmacist Independent Prescriber (GPhC Reg. No: 20-65-651) | UKAAN & Harley Mental Heaalth -Trained | Medical Scientist
Clinical disclaimer:
This article is provided for professional education and general information. It does not constitute an individual clinical assessment, diagnosis or treatment recommendation.
References:
Adamou, M., Arif, M., Asherson, P., Cubbin, S., Leaver, L., Sedgwick-Müller, J., Müller-Sedgwick, U., van Rensburg, K. and Kustow, J. (2024) ‘The adult ADHD assessment quality assurance standard’, Frontiers in Psychiatry, 15, 1380410. doi: 10.3389/fpsyt.2024.1380410. Available at: Full research article.
American Psychiatric Association (2022) Diagnostic and Statistical Manual of Mental Disorders. 5th edn, text revision (DSM-5-TR). Washington, DC: American Psychiatric Association Publishing. doi: 10.1176/appi.books.9780890425787. Available at: DSM-5-TR publication.
DIVA Foundation (n.d.) What is DIVA-5? The Hague: DIVA Foundation. Available at: DIVA Foundation (Accessed: 25 October 2026).
Hong, M., Kooij, J.J.S., Kim, B., Joung, Y.-S., Yoo, H.K., Kim, E.-J., Lee, S.I., Bhang, S.-Y., Lee, S.Y., Han, D.H., Lee, Y.S. and Bahn, G.H. (2020) ‘Validity of the Korean version of DIVA-5: A semi-structured diagnostic interview for adult ADHD’, Neuropsychiatric Disease and Treatment, 16, pp. 2371–2376. doi: 10.2147/NDT.S262995. Available at: Research publication.
Kooij, J.J.S. et al. (2019) ‘Updated European consensus statement on diagnosis and treatment of adult ADHD’, European Psychiatry, 56, pp. 14–34. doi: 10.1016/j.eurpsy.2018.11.001. Available at: European consensus statement.
National Institute for Health and Care Excellence (NICE) (2018) Attention deficit hyperactivity disorder: diagnosis and management. NICE guideline NG87. Published 14 March 2018; subsequently updated, including amendments in May 2025. Available at: NICE NG87 (Accessed: 25 October 2026).
Royal College of Psychiatrists (2023) Attention deficit hyperactivity disorder (ADHD) in adults: Good practice guidance. College Report CR235. Edinburgh: Royal College of Psychiatrists in Scotland. Available at: CR235 clinical guidance.
