ADHD diagnosis in the UK requires a formal specialist assessment — it can't be done by a GP alone, and it can't be self-diagnosed. There are two routes: NHS assessment, which is free but often has a long wait, and private assessment, which is faster but self-funded. Both lead to the same outcome: a clinical diagnosis that opens the door to evidence-based treatment, including medication if appropriate.
Step 1: Starting with your GP
Every UK diagnostic pathway starts with a GP appointment. You don't need to self-diagnose or prove anything at this stage — describe the symptoms and how long they've affected you, and your GP will assess whether a referral for specialist ADHD assessment is appropriate. GPs cannot diagnose ADHD themselves; their role is to rule out other explanations where relevant and make the referral.
Step 2: NHS vs private assessment
NHS route: Free at the point of use, but waiting times for adult ADHD assessment in particular have been widely reported as long in many parts of the UK — sometimes well over a year, depending on your local NHS trust or integrated care board. Waits for children's assessment vary by area too, though are often somewhat shorter.
Private route: Faster in most cases — often weeks rather than months or years — but self-funded, with costs varying by provider. A diagnosis from a properly regulated private provider is a legitimate clinical diagnosis, and many people then move ongoing prescribing to their NHS GP through a shared-care arrangement, though this depends on local NHS policy and individual GP practices.
Some people pursue both routes in parallel — staying on the NHS waiting list while considering a private assessment — which is a reasonable approach given how variable NHS waiting times can be.
Step 3: What the assessment actually involves
A thorough ADHD assessment is more than a quick questionnaire. It typically includes:
- A detailed clinical interview covering current symptoms and their impact on daily life
- A childhood history review, since ADHD symptoms must have been present before age 12
- Standardised, validated rating scales
- Consideration of other conditions that could explain the symptoms (anxiety, depression, sleep disorders, and others)
- Where relevant and available, input from people who knew you as a child, or teachers for a child being assessed
Step 4: After diagnosis
If diagnosed, the specialist discusses treatment options with you — this may include medication, non-medication approaches, or both, based on your individual circumstances. If medication is agreed, the specialist typically initiates and titrates it before handing ongoing prescribing to your GP under a shared-care agreement. See our ADHD treatment guide for what happens next, and our ADHD medication guide for the specific options available.
The NHS Right to Choose route
In England, NHS patients generally have a legal "Right to Choose" which provider carries out their NHS-funded assessment, including some providers that aren't your local NHS trust. Some people use this to access a provider with a shorter waiting list than their local trust, while the assessment remains NHS-funded rather than privately paid. Whether this is available to you, and which providers accept Right to Choose referrals, depends on your GP practice and local NHS commissioning arrangements — ask your GP directly whether this route is open to you, since availability and provider lists change over time.
Choosing a private provider carefully
If you're considering the private route, check that the provider is properly regulated (CQC-registered in England, or the equivalent body in Scotland, Wales or Northern Ireland), that the assessing clinician's qualifications are clearly stated, and that you understand how ongoing prescribing and GP shared care will work before booking — this varies between providers and matters significantly for continuity of treatment.