What are the routes to diagnosis?

There are three main pathways in the UK.

1. NHS referral

You usually start by seeing your GP.

The GP can refer:
• A child → community paediatrics or CAMHS
• An adult → adult ADHD service or psychiatry

The NHS service then triages the referral and places you on a waiting list.

Current NHS waiting times vary significantly across the country and can range from approximately 1 year to several years depending on region and service capacity.

2. Right to Choose (England only)

In England, patients have a legal right to choose an alternative NHS-funded provider.

This is called Right to Choose.

Your GP sends a referral to an approved provider rather than the local NHS service. The assessment is funded by the NHS but carried out by an external specialist clinic.

Not all providers offer medication treatment, and waiting times still apply, but they are often shorter than local NHS services.

3. Private assessment

You can also arrange an assessment directly with a specialist clinician or clinic.

A private diagnosis is made using the same diagnostic criteria (DSM-5) and NICE guidance as NHS assessments. The difference is the funding source, not the diagnostic standard.

After diagnosis, some GPs will enter a shared-care prescribing agreement, although this varies by GP practice and local policy.

What symptoms lead people to seek assessment?

People commonly seek assessment due to longstanding patterns such as:

• difficulty sustaining attention
• chronic disorganisation
• forgetfulness
• emotional dysregulation
• impulsivity
• overwhelm with everyday tasks
• academic or workplace difficulties

Adults often present after years of anxiety or depression treatment where underlying ADHD had not previously been considered.

What happens during an ADHD assessment?

An ADHD assessment is detailed and usually takes considerably longer than a standard medical appointment.

It normally includes several components.

Clinical interview

The clinician asks about:
• childhood behaviour
• education history
• work functioning
• relationships
• daily living skills
• mental health history

ADHD must begin in childhood, even if it was not recognised at the time.

Developmental history

A parent or someone who knew you as a child is often asked to provide information.
For children, parents complete this directly.

This helps confirm symptoms were present before age 12, which is a diagnostic requirement.

Questionnaires and rating scales

Standardised rating scales may be completed by:
• the patient
• parents
• teachers
• partners

These do not diagnose ADHD alone. They support clinical judgement.

School or childhood evidence

For children, teacher feedback is essential.
For adults, school reports or parental accounts are very helpful.

ADHD requires impairment in more than one setting (for example school and home, or work and home).

Diagnostic criteria

The clinician compares the information gathered against DSM-5 criteria.

To meet diagnostic threshold:
• several symptoms must be present
• they must be persistent
• they must cause functional impairment
• they must have been present since childhood
• they must not be better explained by another condition

MDT review

Many services use a multidisciplinary team (MDT).
This means more than one clinician reviews the information before confirming diagnosis.

This increases diagnostic reliability.

Is there a test or brain scan for ADHD?

No.

ADHD cannot currently be diagnosed by:
• blood tests
• MRI scans
• brain scans
• computer attention tests alone

Computerised tests may be supportive tools but are not diagnostic in isolation. Diagnosis remains clinical.

What happens after diagnosis?

If ADHD is diagnosed, you will receive a written clinical report.

Next steps may include:

• psychoeducation (understanding ADHD)
• school or workplace adjustments
• behavioural strategies
• coaching or therapy
• medication discussion

Medication is not mandatory. Some people choose non-medication management.

Can adults really be diagnosed if they were never diagnosed as a child?

Yes.

Many adults were not recognised in childhood, particularly:
• girls
• academically able children
• people who masked symptoms

The key requirement is evidence symptoms were present during childhood, not that a diagnosis existed at the time.

What if it isn’t ADHD?

An assessment may identify alternative or additional explanations, for example:

• autism spectrum condition
• anxiety disorders
• trauma-related difficulties
• learning difficulties
• sleep disorders

A proper assessment is therefore still useful even when ADHD is not diagnosed.

Why a proper assessment matters

ADHD overlaps with many other conditions. A brief or checklist-only assessment risks misdiagnosis.

A thorough assessment:
• prevents inappropriate medication
• identifies co-existing conditions
• supports schools and workplaces
• allows appropriate treatment planning

Summary

ADHD diagnosis in the UK is a structured clinical process based on developmental history and current impairment across multiple settings. It can occur through NHS services, Right to Choose providers, or private specialist clinics.

The key point is not where the assessment takes place, but how it is conducted — a comprehensive, evidence-based assessment following NICE guidelines.