Guide · Updated May 2026
ADHD and Autism — Understanding the Overlap and Getting a Combined Assessment
Around 40% of people with ADHD also meet criteria for autism. Here is what that means for diagnosis, and how a combined assessment works.
How common is the overlap between ADHD and autism?
Research consistently shows that ADHD and autism co-occur far more often than chance would predict. Studies estimate that approximately 40% of people diagnosed with ADHD also meet criteria for autism spectrum condition (ASC), and around 50–70% of autistic people show significant ADHD traits. A landmark 2010 study by Lichtenstein et al. in The Lancet confirmed strong genetic links between the two conditions, suggesting they share underlying neurobiological mechanisms.
This matters for diagnosis and treatment because when one condition is present and the other is missed, the picture is incomplete. ADHD medication, for example, can be highly effective for attention and impulse control, but will not address the sensory sensitivities or rigid thinking patterns associated with autism. Equally, support strategies designed for autism may not account for the impulsivity and emotional dysregulation driven by ADHD. Getting an accurate picture of both conditions leads to more targeted, effective support.
Key statistic: Approximately 40% of people with ADHD also have autism. Both conditions are significantly underdiagnosed in women and in people who mask effectively.
How ADHD and autism overlap — and how they differ
ADHD and autism share a number of traits that can make them difficult to distinguish from one another — and even harder to identify when both are present. Understanding the overlap helps explain why so many people receive one diagnosis without the other being explored.
Executive function difficulties
Both conditions affect planning, organisation, task-switching, and working memory. In ADHD this is often driven by dopamine dysregulation; in autism it is associated with a preference for routine and difficulty with cognitive flexibility.
Sensory sensitivities
Sensory processing differences are a core feature of autism, but are also very common in ADHD. Sensitivity to noise, light, textures, or temperature is frequently reported by people with both conditions.
Social differences
Autism involves differences in social communication and interaction. ADHD can cause social difficulties through impulsivity, interrupting, and difficulty reading social cues. When both are present, social challenges are often more pronounced.
Emotional regulation
Rejection sensitive dysphoria (RSD) is closely associated with ADHD. Autistic people often experience intense emotional responses and difficulty regulating them. The combination amplifies both.
Masking and late diagnosis
Women are particularly likely to have both conditions missed. Masking — adapting behaviour to fit neurotypical expectations — is common in both autism and ADHD, and is more prevalent and more effective in women. The result is that both conditions go undetected until a crisis or life transition makes compensation impossible.
Women are particularly likely to have both conditions missed. Read our guide on ADHD in women for more on how masking delays diagnosis.
What is a combined ADHD and autism assessment?
A combined assessment evaluates for both ADHD and autism simultaneously, conducted by a clinician experienced in both conditions. Rather than attending two separate appointments with potentially different clinicians, you go through a single structured process — typically involving a detailed clinical interview, standardised questionnaires for both conditions, and a review of developmental history — and receive one comprehensive report at the end.
There are two key advantages to this approach.
More accurate
Because the clinician assesses for both at once, they can see how the two conditions interact and which symptoms belong to which diagnosis — reducing the risk of one masking the other.
More efficient
One assessment process, one report, one set of appointments. Usually quicker and cheaper than having two separate assessments done independently.
If you are unsure whether you need a combined assessment, speak to the clinic directly before booking. Many will advise on the most appropriate assessment pathway based on your history.
How much does a combined assessment cost in the UK?
Combined assessments are usually more cost-effective than two separate assessments. Here is how the typical UK private costs compare:
| Assessment type | Typical UK cost |
|---|---|
| ADHD assessment (standalone) | £500 – £1,500 |
| Autism assessment (standalone) | £800 – £2,000 |
| Combined ADHD & Autism assessment | £1,000 – £2,500 |
Prices vary significantly between providers and depend on the length of the assessment, the seniority of the clinician, and whether it is conducted in person or remotely. Always confirm costs directly with the clinic before booking.
For a detailed breakdown of what drives ADHD assessment pricing, see our ADHD assessment cost guide.
Finding a UK clinic that offers combined assessments
Not all ADHD clinics offer autism assessments. When searching, use the Combined ADHD & Autism filter on any city page to see only clinics that offer this service. You can also use the list below, which is updated as clinics are verified.
Aberdeen
All Aberdeen clinics →Aberdeen, AB10
Price
£1,200 – £1,800
Wait time
~3 weeks
Format
In-person only
Ages
All ages
Consultant-led paediatric ADHD and autism assessments at Golden Square, Aberdeen. Dr Hanan Hamed and Dr Marianne Forrester — both with decades of NHS experience. In-person assessments for children. No referral required.
Birmingham
All Birmingham clinics →Price
Call for pricing
Wait time
~1 weeks
Format
Online & in-person
Ages
All ages
Private ADHD clinic offering fast assessments for adults and children in Birmingham. Same-day appointments available with no referral needed. Psychiatrist and specialist clinician-led evaluations using recognised diagnostic tools. Free initial consultation. Face-to-face and online options.
Birmingham, B1 1BD
Price
From £895
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Established private mental health clinic offering comprehensive ADHD assessments in Birmingham. Psychiatrist and psychologist-led evaluations for adults and children. In-person appointments plus online video assessments available. Part of a national network with clinics across the UK.
Birmingham, B73 6RJ
Price
Call for pricing
Wait time
~1 weeks
Format
In-person only
Ages
All ages
In-person only ADHD and autism assessment service in Sutton Coldfield, led by HCPC-registered Clinical Psychologists. 100% NHS acceptance rate for reports. Neuroaffirming approach considering masking and gender differences. Comfortable home-from-home clinic setting at Lyndon House.
Brighton
All Brighton clinics →Brighton, BN1
Price
£380 – £2,100
Wait time
~3 weeks
Format
Online & in-person
Ages
Adults
Private ADHD assessments for adults and young people aged 16+. Clinics in Brighton and London with online option. Consultant psychiatrist-led assessments with detailed clinical reports and treatment recommendations.
Dundee
All Dundee clinics →Dundee, DD1 1NQ
Price
From £1,700
Wait time
~4 weeks
Format
Online & in-person
Ages
All ages
Multi-disciplinary ADHD and autism assessment clinic based in central Dundee. Team includes clinical psychologists, educational psychologists, occupational therapists and speech therapists. Gold standard assessments with both a psychiatrist and clinical psychologist. In-person at their Dundee clinic on South Tay Street or remote UK-wide. Sister practice The St Andrews Practice in Fife.
Edinburgh
All Edinburgh clinics →Edinburgh
Price
Call for pricing
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Specialist psychiatric practice in Edinburgh's New Town offering ADHD assessments for children, adolescents and adults. 20 years of clinical expertise. Face-to-face and online appointments available. Fees shown transparently in booking portal by clinician. No GP referral required.
Exeter
All Exeter clinics →Exeter, EX1
Price
£595 – £2,495
Wait time
~8 weeks
Format
In-person only
Ages
All ages
HCPC registered clinicians using QB diagnostic screening and DIVA-5 tools. ADHD, autism and combined assessments for adults and children. Flexible payment plans available.
Exeter, EX1
Price
£695 – £895
Wait time
Not listed
Format
Online & in-person
Ages
All ages
Purpose-built assessment centre offering ADHD, autism and SpLD assessments. NHS Right to Choose pathway available. Gold-standard diagnostic tools. Trusted by NHS commissioners and recommended by ADHD UK.
Glasgow
All Glasgow clinics →Glasgow, G2
Price
£950 – £1,250
Wait time
~3 weeks
Format
In-person only
Ages
All ages
Glasgow-based neurodivergent team led by Dr Emma Field. Face-to-face ADHD and autism assessments in central Glasgow offices plus online UK-wide. Evidence-based diagnostic process for children, adolescents and adults. Post-diagnostic coaching, therapy and prescriber referral network.
Glasgow, G2
Price
£800 – £1,200
Wait time
~3 weeks
Format
In-person only
Ages
All ages
Comprehensive private ADHD assessments in Glasgow. Evidence-based diagnostic tools with expert analysis. Assessments for children and adults including second opinions. Detailed personalised diagnosis reports.
Leeds
All Leeds clinics →Leeds
Price
£495 – £575
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Comprehensive ADHD assessments starting from £495 for adults. Available in-person in Liverpool and Leeds or via video link across the UK. Full psychiatric assessment including physical health review, family history and symptom impact analysis. Also offers children's ADHD assessments.
Leicester
All Leicester clinics →Leicester, LE7 9QB
Price
£750 – £1,200
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Private ADHD assessment service at The Health Suite, Uppingham Road, Leicester. Part of Clinical Partners' national network. Offers psychiatrist-led assessments for adults and children with comprehensive reports and treatment recommendations.
Liverpool
All Liverpool clinics →Liverpool
Price
£495 – £575
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
ADHD assessment clinic with a dedicated children's sensory-appropriate space in Liverpool. Adult assessments from £495. Specialist in-person children's assessments in a neurodiverse-friendly environment. Also offers video assessments UK-wide.
London
All London clinics →London, EN5 5TW
Price
Call for pricing
Wait time
~1 weeks
Format
Online & in-person
Ages
All ages
Specialist ADHD clinic with locations in central London and Barnet. Led by Dr Khurram Sadiq, a world-renowned psychiatrist and TEDx speaker on ADHD and autism. Offers ADHD, autism and combined AuDHD assessments. Weekend appointments available. In-person and online options.
London, NW7 1PL
Price
£750 – £800
Wait time
~3 weeks
Format
In-person only
Ages
All ages
Private hospital offering ADHD assessments for adults from £750 (online) or £800 (in-person) and children from £990. 80-minute assessment sessions with detailed diagnostic reports. Follows NICE guidelines ensuring NHS recognition. First prescription cost included if medication is appropriate.
London, W1G 9PF
Price
Call for pricing
Wait time
~0 weeks
Format
Online & in-person
Ages
All ages
Harley Street practice offering specialist ADHD assessments for adults and children, both in-person and via video consultation. Provides private prescriptions and medication management with home delivery. Located at 10 Harley Street, London.
London
Price
Call for pricing
Wait time
~8 weeks
Format
Online only
Ages
Adults
Right to Choose ADHD provider offering NHS-funded adult assessments across England. Approximately 8 week wait time. Fully online video assessments. Also offers private assessment pathway. CQC registered.
London, W1G 8YL
Price
£695 – £1,695
Wait time
~1 weeks
Format
Online & in-person
Ages
All ages
Leading UK ADHD assessment and treatment provider with clinics on Wimpole Street, London and Wilmslow Road, Manchester. Consultant psychiatrist-led assessments lasting 60-90 minutes using DSM-V criteria. Offers shared care agreements with GPs for ongoing prescribing. Operating since 2009.
Manchester
All Manchester clinics →Manchester
Price
Call for pricing
Wait time
~1 weeks
Format
Online & in-person
Ages
Adults
Specialist adult ADHD clinic in Manchester using validated screening tools, structured clinical interviews and cognitive profiling. Neurodivergent-affirming approach. Full diagnostic reports with next-step recommendations. Free ADHD screening test available. No referral required.
Manchester, M3 3AQ
Price
From £1,495
Wait time
~2 weeks
Format
In-person only
Ages
All ages
In-person ADHD and autism assessment centre in Spinningfields, Manchester. Child ADHD assessments at £1,495 including initial consultation. Uses QB diagnostic screening technology and DIVA-5 tools. HCPC registered clinicians with NICE-compliant gold standard assessments. Flexible payment plans available.
Manchester, M20 3QD
Price
£69,500 – £169,500
Wait time
~1 weeks
Format
Online & in-person
Ages
All ages
Manchester branch of the UK's leading ADHD assessment provider, located on Wilmslow Road. Consultant psychiatrist-led assessments lasting 60-90 minutes. Offers adult, child and student ADHD assessments. Shared care agreements available with GPs for medication prescribing.
Nottingham
All Nottingham clinics →Nottingham, NG2 5BB
Price
£750 – £1,200
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Located in West Bridgford, Nottingham. Private ADHD assessments for adults and children. Psychiatrist and psychologist-led evaluations with detailed diagnostic reports. Both face-to-face and video appointments available.
Online
All Online clinics →Online
Price
£750 – £950
Wait time
~2 weeks
Format
Online & in-person
Ages
All ages
Online private ADHD assessments available UK-wide. Rated Good by Healthcare Improvement Scotland. Consultant psychiatrist-led. BUPA insurance accepted. Personalised treatment plans including medication, therapy and CBT.
Online
Price
£950 – £1,950
Wait time
~8 weeks
Format
Online only
Ages
All ages
Major Right to Choose provider. Free ADHD assessment via NHS RtC pathway or private from £799. CQC registered. Online video assessments available nationwide.
Sheffield
All Sheffield clinics →Sheffield
Price
£59,500 – £69,500
Wait time
~1 weeks
Format
Online only
Ages
All ages
Online ADHD assessments covering Sheffield and South Yorkshire. Adults from £595, children from £695 including VAT. Led by experienced NHS consultant psychiatrists. Diagnostic reports within 5 working days. GP shared care agreements arranged.
Southampton
All Southampton clinics →Southampton, SO14
Price
£1,495 – £2,495
Wait time
~8 weeks
Format
In-person only
Ages
All ages
HCPC registered clinicians using NICE-compliant gold standard diagnostic tools. Adult and child ADHD assessments plus combined autism/ADHD assessments. In-person at Southampton hub with free parking.
Common questions
Can I get assessed for ADHD and autism at the same time?
Yes. A number of UK clinics offer combined ADHD and autism assessments conducted in a single process. The clinician assesses for both conditions simultaneously, which means fewer appointments, one comprehensive report, and a more accurate picture of how the two conditions interact in your specific case.
Is a combined assessment more expensive than separate assessments?
Usually not — combined assessments typically cost less than having two separate assessments done independently. A standalone private ADHD assessment costs roughly £500–£1,500, while a standalone autism assessment costs £800–£2,000. A combined assessment covering both usually comes in at £1,000–£2,500, making it the more cost-effective option for people who suspect both conditions.
Will my GP accept a combined private diagnosis?
Most GPs will accept a private diagnosis from a registered provider and use it to inform shared care arrangements. If the clinician is registered with the relevant professional body (for example, the GMC or HCPC) and the report is comprehensive, your GP should be able to work with it. It is worth confirming with your GP practice before booking.
Can I use NHS Right to Choose for a combined assessment?
The NHS Right to Choose scheme is specifically for ADHD assessments. It does not currently extend to autism assessments. If you want a combined assessment through Right to Choose, check with your GP and the provider directly — some providers can conduct the ADHD element under Right to Choose and the autism element separately, though this varies.
What happens after a combined diagnosis?
Following a combined ADHD and autism diagnosis, you will typically receive a comprehensive written report with recommendations. For ADHD, this may include medication and/or behavioural strategies. For autism, it may include strategies for sensory needs, communication, and workplace adjustments. Your clinician will usually recommend a follow-up with your GP to discuss shared care and any medication, as well as signposting to relevant support organisations.
This guide was last updated May 2026. Statistics are drawn from published research including Lichtenstein et al. (2010), The Lancet. This page is for informational purposes only and does not constitute medical advice. If you are concerned about your symptoms, speak to a qualified clinician.