Getting an ADHD Assessment

What is an ADHD assessment?

An ADHD assessment is a detailed clinical evaluation carried out by a specialist. It is designed to determine whether your difficulties are consistent with ADHD, and to rule out other explanations for your symptoms.

ADHD can only be diagnosed by a specialist psychiatrist, paediatrician, or another qualified clinician with specific training and expertise in ADHD. This is set out in NICE guideline NG87.¹

Routes to assessment

NHS assessment through your GP

The most common route is through your GP. If your GP agrees that your difficulties are consistent with ADHD, they will refer you to a specialist ADHD service for assessment.

Current NHS waiting times for ADHD assessment vary enormously across England. Some areas have waits of 18 months to 2 years. In others, the wait is 5, 10, or even 15 years. The ADHD Taskforce confirmed that NHS ADHD services are under extreme pressure.²

Right to Choose

In England, if your GP agrees to refer you, you have the legal right to choose which NHS-approved provider carries out the assessment. This is known as the Right to Choose and can significantly reduce waiting times.

Private assessment

You can choose to pay for a private assessment. Costs vary, typically ranging from 500 to 1,500 pounds depending on the provider. If you receive a private diagnosis, your GP may agree to a Shared Care Agreement to provide ongoing prescribing and monitoring through the NHS. This is not guaranteed and depends on local policy.

What happens during an assessment

Overview of the process

A comprehensive ADHD assessment typically includes several components. The exact format varies between providers, but the core elements are consistent:¹

A detailed clinical interview covering your current symptoms, how they affect your daily life, your developmental history from childhood, your educational and employment history, your relationship and social history, and your mental health history.

A review of childhood symptoms. ADHD is a neurodevelopmental condition - symptoms must have been present from childhood, even if they were not recognised at the time. The assessor will explore your early experiences in detail.

Collateral information. Ideally, the assessor will also gather information from someone who knew you as a child - a parent, sibling, or other family member. This helps corroborate your developmental history. If collateral information is not available, a thorough assessment can still proceed, but the clinician will note this.

Standardised rating scales and questionnaires. These may include the DIVA (Diagnostic Interview for ADHD in Adults), the ASRS, or the CAARS. These tools help the assessor systematically evaluate your symptoms against diagnostic criteria. See our guide to ADHD screening tools for more detail.

Assessment of functional impairment. ADHD diagnosis requires that symptoms cause clinically significant impairment in at least two areas of life (such as work, relationships, education, or daily functioning).¹

Screening for co-occurring conditions. Many people with ADHD also have other conditions - anxiety, depression, autism, sleep disorders, or learning difficulties. A good assessment will screen for these because they affect both diagnosis and treatment planning.

What the assessor is looking for

The assessor is not simply counting symptoms. They are looking at the overall pattern: whether the difficulties are consistent with ADHD rather than another explanation, whether they have been present since childhood, whether they cause significant impairment, and whether they are best explained by ADHD or by another condition (or both).

The role of childhood informants

Why childhood information matters

ADHD is defined as a neurodevelopmental condition, meaning it begins in childhood. The current diagnostic criteria (DSM-5 and ICD-11) require evidence that symptoms were present before age 12, even if the diagnosis is being made in adulthood.¹

This is why assessors ask for information about your childhood. They may ask you directly about your school experience, but they may also ask to speak with or receive a questionnaire from someone who knew you as a child.

What if you do not have a childhood informant?

Not everyone has access to someone who can provide childhood information. A parent may have died, you may be estranged from your family, or you may have been in care. This does not mean you cannot be assessed.

If you have school reports, old letters from teachers, educational psychology assessments, or similar documents, these can be useful evidence. Some people find it helpful to write down their childhood memories before the assessment.

How to prepare

Before the assessment

There are practical steps you can take to get the most from your assessment:

• Complete any pre-assessment questionnaires sent by the provider. These may include screening tools like the ASRS or a developmental history form.
• Gather childhood evidence if you can: school reports, any previous psychological or educational assessments, letters or notes from teachers.
• Identify a childhood informant if possible. This is usually a parent, but could be an older sibling, aunt, uncle, or anyone who knew you well as a child. Some providers send a separate questionnaire for the informant to complete.
• Write down your key difficulties. Think about how ADHD symptoms affect you now - at work, in relationships, in daily life, with organisation, with emotional regulation.
• Note any mental health history. Previous diagnoses, medications, therapy - these are all relevant to the assessment.
• List your questions. The assessment is also your opportunity to ask the specialist about your experience.

During the assessment

• Be honest about your experiences. The assessor is there to understand your difficulties, not to judge them.
• It is normal to feel nervous. Some people find that ADHD symptoms actually improve slightly under pressure or novelty (this is part of the condition), so you may feel more focused during the assessment than in everyday life. This is expected.
• The assessment may take 1 to 3 hours, depending on the provider and format. Some providers split it across multiple sessions.

After the assessment

You should receive a written report, typically within a few weeks. The report will set out whether you meet diagnostic criteria for ADHD, the reasoning behind the decision, and recommendations for next steps - which may include medication, therapy, coaching, or workplace adjustments.

If you are diagnosed with ADHD, you may be offered medication as part of your treatment. If medication is recommended, the specialist will usually initiate and stabilise it before transferring your ongoing care to your GP through a Shared Care Agreement.

Quality of assessment

What a good assessment looks like

The UK Adult ADHD Network (UKAAN) has developed quality standards for adult ADHD assessment. A high-quality assessment should include:³

• A full developmental history going back to early childhood
• Assessment of current symptoms and their impact on functioning
• Collateral information (where available)
• Screening for co-occurring conditions
• Use of standardised tools alongside clinical judgement
• A written report with clear reasoning

What to watch out for

Some assessments - particularly some rapid online assessments - may not meet these standards. Be cautious if an assessment:

• Takes less than 30 minutes
• Relies solely on a questionnaire without a clinical interview
• Does not ask about your childhood
• Does not screen for other conditions
• Does not produce a written report

If you are not diagnosed

Not everyone who is assessed will receive an ADHD diagnosis. This does not mean your difficulties are not real. It may mean that your symptoms are better explained by another condition, that the evidence for childhood onset was not strong enough, or that your difficulties, while genuine, do not quite meet the clinical threshold.

If you are not diagnosed but feel the assessment did not fully capture your experience, you have the right to seek a second opinion. You may also wish to explore whether other conditions - such as autism, anxiety, or a sleep disorder - could explain your difficulties.

Getting support

Useful organisations

• ADHD UK - information, support, and advocacy
• AADD-UK - support for adults with ADHD
• ADHD Foundation - the neurodiversity charity

neurobetter resources

• ADHD - understanding ADHD as a whole
• Right to Choose - choosing your assessment provider
• Screening tools - self-report tools that can help you prepare
• Getting a diagnosis - the broader diagnostic landscape
• Late diagnosis - discovering ADHD in adulthood
• Our Local Services directory - find ADHD services near you
• Our online community - connect with others who understand
• Ask a Counsellor - private, confidential guidance