If you are weighing up whether to pursue an NHS or private ADHD assessment for yourself or your child, the most honest starting point is this: neither route is automatically better. The right choice depends on your circumstances, how urgently you need clarity, and what ongoing support you are likely to need. 

This guide compares both routes fairly, explains what a thorough assessment should include regardless of route, and gives you the questions worth asking before you book.

Key Takeaways:

• NHS and private ADHD assessments can both be valid routes to diagnosis and support
• The quality of the assessment matters more than the route; rating scales alone are not sufficient
• NHS waiting times vary significantly by area; some adults wait several years
• Private assessment from ADHD Certify automatically offers you a faster yet NHS like standard route
• A good assessment covers developmental history, impairment across settings, and considers co-existing conditions

What is the difference between NHS and private ADHD assessment?

The difference between NHS and private ADHD assessment is primarily one of access, timing, and funding rather than diagnostic standards. Both routes should use the same clinical criteria drawn from NICE guidelines.¹ Both should result in a written report. Both can lead to a formal diagnosis and, where appropriate, medication.

The NHS route is free at the point of use. It typically starts with a GP referral, followed by assessment at a specialist ADHD clinic or community mental health team. The private route bypasses the waiting list, is funded directly by you, and gives you more choice over provider and timing.

What they share is the same clinical standard. A diagnosis is only as reliable as the quality of the assessment behind it.

What a good ADHD assessment should include

Regardless of whether you choose NHS or private, a thorough ADHD assessment should go well beyond a checklist or rating scale. NICE guidelines set out clearly what a specialist assessment should cover.¹

A thorough assessment includes a detailed developmental and psychiatric history from childhood, because ADHD is a neurodevelopmental condition that begins early in life even when it goes unrecognised for years. It examines how symptoms affect functioning across multiple settings, not just in one context. It gathers observer information, such as input from a partner, parent, or school, rather than relying on self-report alone. It considers co-existing conditions such as anxiety, depression, autism, or learning difficulties, because these are common and can significantly affect how ADHD presents.

A clinician relying only on a brief questionnaire or a single appointment without developmental history is not meeting the standard that NICE recommends. This applies whether you are going through the NHS or paying privately.

Our What is ADHD? page explains the condition and its diagnostic criteria in straightforward terms.

NHS vs private: Practical differences

Local NHS policies on shared care, which determines whether your GP will take over prescribing after a private diagnosis, vary. It is worth checking your GP’s policy before proceeding with a private assessment if ongoing medication is likely to be relevant.

NHS ADHD assessment: What to expect

For adults, the NHS route typically begins with a conversation with your GP. If the GP agrees that an assessment is appropriate, they will refer you to a local specialist service, which may be a psychiatric service, a community mental health team, or a dedicated ADHD clinic depending on where you live.¹

For children, parents can speak to their GP and also to the child’s school or SENCO. School input is useful clinical information. Referral then goes to a paediatrician or specialist CAMHS team.

Waiting times vary considerably by region. In some parts of England, adults are waiting several years.² The NHS ADHD Taskforce report published in 2025 found that approximately 40% of surveyed commissioners and clinicians reported waiting times of two years or more for adults. This is a real barrier for many people, particularly when difficulties are significantly affecting daily life.

Private ADHD assessment: What to check before booking

A private assessment can offer faster access and more choice over provider. But paying privately does not automatically guarantee a higher quality assessment. Before booking, it is worth checking several things.

The clinician’s credentials matter. For adults, an ADHD assessment in the UK should be conducted by, or under the clinical supervision of, a consultant psychiatrist, clinical psychologist, or specialist nurse prescriber with relevant expertise.¹ For children, a paediatrician or child psychiatrist with ADHD training is appropriate.

Ask how long the assessment takes and what it includes. A comprehensive assessment typically involves at least one extended clinical interview, a detailed developmental history, validated rating scales used as one part of the picture, and a full written report with the clinician’s clinical reasoning. Ask whether the assessment includes consideration of co-existing conditions and what happens after diagnosis if medication or further support is needed. Ask whether the provider will communicate with your GP.

A very brief process or one based primarily on questionnaires alone is a quality concern regardless of cost.

Questions to ask before choosing

Before committing to either route, five questions are worth considering.

How long has the waiting time been locally, and how is that affecting you or your child now? Is the difficulty causing significant and ongoing impairment? What credentials does the clinician hold, and does the assessment process match NICE standards? What happens after diagnosis: is there a clear pathway to medication, support, or follow-up? And will the report you receive be accepted by your GP, employer, university, or other services you may need to access?

If you are ready to explore a private route that meets clinical standards, our ADHD assessment for adults and ADHD assessment for children both include a full written diagnostic report. Appointments are available within the same week in many cases.

Frequently Asked Questions.

References

[1] National Institute for Health and Care Excellence (2018, last reviewed 2026) Attention deficit hyperactivity disorder: diagnosis and management. NICE guideline NG87. Available at: https://www.nice.org.uk/guidance/ng87/chapter/recommendations

[2] NHS England (2025) Report of the independent ADHD Taskforce: Part 1. Available at: https://www.england.nhs.uk/long-read/report-of-the-independent-adhd-taskforce-part-1/