Some psychologists can diagnose a mental health condition, but you don’t need a diagnosis to start therapy. A clinical psychologist registered with the Health and Care Professions Council (HCPC) may give a diagnosis where it helps you. Many work with a formulation instead, which explains what is going on for you without naming a condition. You don't need a diagnosis to start therapy, and psychologists can't prescribe medication.
If you have asked a clinic for a diagnosis, the first question is what you want it for. The answer decides what to ask for.
Who can diagnose mental health conditions in the UK?
It depends on the condition and on the training of the person you see. For ADHD, NICE says the diagnosis should come from a specialist psychiatrist, a paediatrician (a children's doctor) or another appropriately qualified healthcare professional. They need training in ADHD. NICE also asks for a full assessment of your symptoms, history and everyday life, not a rating scale on its own.
Adult ADHD and autism assessments with us are carried out by HCPC-registered clinical psychologists, and the report includes a diagnosis if one is relevant.
Which psychologists and therapists are registered to practise?
The word "psychologist" on its own is not protected by law in the UK, so anyone can use it. Nine titles are protected, including clinical psychologist and counselling psychologist, and anyone using one must be on the HCPC Register. "Counsellor", "psychotherapist" and "therapist" are not protected titles, and our guide to psychologist vs counsellor explains how the roles differ.
Before you book, search the name on the HCPC Register.
When does a psychiatrist diagnose instead?
A psychiatrist is a medical doctor who specialises in mental health, a field called psychiatry. They can diagnose and treat mental health conditions, including with medication, which psychologists can't prescribe. If medication is your main reason for an assessment, start with a psychiatrist. We would be happy to recommend one, and our guide to the difference between a psychologist and a psychiatrist covers who does what.
What is the difference between a diagnosis and a psychological formulation?
A diagnosis names a condition using recognised clinical criteria. A psychological formulation is a personal explanation of what is happening for you, how it started and what keeps it going. A clinician can use both.
| Compare | Diagnosis | Psychological formulation |
|---|---|---|
| What it is | A named condition, based on recognised clinical criteria | A personal explanation of your difficulties and strengths |
| What you get | A name for your condition, and a route to treatment or medication | A shared understanding that guides your therapy |
| Best when | You need it for treatment, medication or a report | You want to understand what is going on and what could help |
| Limit | It names the condition. It says less about why it started for you | It does not name a condition, so it won't unlock services that ask for a diagnosis |
What a clinical diagnosis gives you
A diagnosis can lead to a treatment pathway and, where it suits you, medication. Your psychologist can also write a report for your GP, your school or your employer. Some autistic adults find a late diagnosis a relief, because it helps them make sense of past experiences.
What a formulation gives you
A formulation looks at how your difficulties began, what keeps them going and what helps, including your strengths. The Open University's course on mental health describes it as a working explanation that can change over time. It guides the support you are offered without needing a formal diagnosis. We offer both diagnosis and formulation.
Do you need a diagnosis to get therapy?
No. The NHS says you do not need a diagnosed mental health condition to get talking therapies, and you can refer yourself for anxiety and depression. Some conditions, such as eating disorders, bipolar disorder and psychosis, usually need a GP referral on the NHS.
It is the same with us. You can start talking therapy, also called psychotherapy, without a diagnosis or a GP referral. That covers conditions such as anxiety and depression, and support for autistic adults who have no formal diagnosis.
When is a diagnosis worth having?
A diagnosis is worth having when something specific depends on it. That might be a treatment that needs a confirmed condition, or medication. It might be a workplace or school process that asks for a report, or an answer you have wondered about for years.
A formulation can be enough when your main aim is to understand yourself and have therapy that fits.
Will the NHS accept a private mental health diagnosis?
It depends on the service, and nothing guarantees it. A private assessment does not necessarily skip NHS waiting lists, and an NHS service may want to carry out its own. The NHS ADHD page and the local integrated care board's page don't say whether they accept private diagnoses, so ask before you pay.
Waiting times for NHS-funded assessments in the North East are long. As of October 2026, the NHS North East and North Cumbria Integrated Care Board (ICB) gives a minimum wait. Its funded providers are working to approximately 78 weeks for an initial ADHD or autism assessment. A private assessment with us needs no GP referral.
What happens with ADHD medication?
The NHS says ADHD medicines must be started and monitored by an ADHD specialist. Your GP can take over prescribing only under a shared care agreement, which is a written arrangement between you, your GP and the specialist.
As of October 2026, the NHS North East and North Cumbria ICB says GP practices choose whether to sign one. They can decline for clinical or capacity reasons. The ICB also says the NHS does not fund private assessments.
After a private diagnosis, you can ask your GP for a referral to a Right to Choose treatment-only service. Right to Choose is the NHS rule that lets you pick which service you are referred to. Your GP has to support the referral clinically, and the ICB puts the wait at about 78 weeks from acceptance.
What should you check before you pay?
Before you book, tell your psychologist what you need the report for, because they agree its purpose with you before the assessment starts. If you want the NHS to use it, ask your GP three things:
- Will you accept a private report to support a referral?
- Would you sign a shared care agreement if medication is recommended?
- Does the NHS service I would use need its own assessment first?
Who should you see if you want medication?
Your GP or a psychiatrist. On the NHS, your GP is the first step. Privately, we work alongside Dr Vishaal Goel, a consultant psychiatrist at Integra Psychiatry. You can ask our Pathway Team about an appointment with him. It is common to see a psychiatrist for medication and a psychologist for therapy at the same time.
What happens at a private psychological assessment?
An assessment uses standardised, evidence-based tests to look at one question in depth, such as whether you have adult ADHD. It is separate from therapy, and you can have it on its own or alongside therapy.
You receive a written report. It sets out the purpose, the methods used, the findings, a diagnosis if one is relevant, and recommendations. Your psychologist agrees what the report is for before you start. Assessments take place at our Newcastle and Tynemouth clinics, and online. You don't need a GP referral. As of October 2026, psychological assessments start from £350. Our fees page has the full list, and our Pathway Team, who match you with the right clinician, will confirm which fee applies.
Conclusion
So, can a psychologist diagnose? Some can, and the right choice depends on what you want the answer for.
Which should you ask for?
- If you want to understand what is going on and get therapy that fits, ask for a psychological formulation. Start with therapy with our psychologists.
- If you want a diagnosis for treatment, a report or an answer, ask for a diagnostic assessment. Start with our specialist assessments.
- If you want to start medication, ask for a psychiatrist or your GP. Start with our guide to psychologists and psychiatrists.
This article is for information only and does not replace clinical advice. It has been reviewed by our clinical and editorial team. If you are worried about your mental health, speak to your GP.
