Summary
Getting an autism or ADHD diagnosis requires navigating a system that was not designed for the people who need it. Across Europe and the UK, the pathway from first concern to confirmed diagnosis is long, inconsistent, and shaped more by geography and luck than by clinical need. Adults wait years. Children wait months to years. The experience is routinely described as stressful, confusing, and adversarial. The system is in crisis, and the crisis is getting worse.
This page documents what diagnostic pathways look like in practice: who controls them, how long they take, what the experience is like for autistic people and their families, and where the system is breaking down. It draws on the ASDEU project (the largest European survey of autism services), Scotlandâs pathfinder work through the National Autism Implementation Team (NAIT), UK-wide research, and the emerging consensus that the current model cannot hold.
What the evidence shows
Waiting times
The numbers are stark. In Scotland, over 23,000 adults were waiting for neurodevelopmental assessment as of March 2025, with median waits of 252 days for adults and 525 days for children. Some areas report waits exceeding five years. The number waiting has increased by over 2,200% in some health boards since 2020. In February 2025, NHS Aberdeenshire disbanded its adult autism assessment team entirely.
Across the UK, over 200,000 people are waiting for autism assessment. In England, autism assessment referrals only began to close faster than they opened in June 2025 â the first time since April 2019.
The European picture is no better. Mendez et al. (2023), analysing care pathways in Italy, Spain, and the UK, found long waits from first parental concern to screening, from screening to confirmed diagnosis, and from diagnosis to any form of intervention. The pattern was consistent across all three countries: families described the process as complex, long, and stressful.
NAITâs retrospective analysis of 202 adult cases (assessed October 2021 to May 2022) found significant variation across Scotland, with some health boards having no adult neurodevelopmental pathway at all. The variation is not random â it reflects whether a local area has invested in assessment infrastructure, which depends on local priorities and funding rather than national standards.
What the diagnostic experience is like
Radev et al. (2024) conducted a meta-ethnography of 15 UK qualitative studies examining how autistic adults experience healthcare. Three themes emerged. First, professionalsâ lack of knowledge is actively damaging: misdiagnosis, inappropriate treatment, and dismissal are common. Second, the processing demands of healthcare systems â forms, phone calls, waiting rooms, unpredictable appointments â are themselves barriers. Third, adaptations that would improve engagement (longer appointments, written information, sensory-appropriate environments, consistency of clinician) exist in principle but are rarely implemented in practice.
The diagnostic assessment itself can be experienced as adversarial. Hayes et al. (2021) observed autism assessment teams in the UK and found that clinicians routinely deal with âcontradictionâ â the person in front of them doesnât match the clinical stereotype, has learned to mask, or presents with co-occurring conditions that complicate the picture. The assessment becomes a negotiation about whether the person is âautistic enoughâ rather than an exploration of their neurodevelopmental profile.
For women, the experience is compounded. Harmens et al. (2022) found that autistic womenâs diagnostic journeys interact with identity in complex ways: diagnosis reshapes self-understanding, but the pathway to it involves years of being told nothing is wrong, being given partial diagnoses (anxiety, depression, personality disorder), and learning to doubt their own experience. Nikolova-Fontaine and Egilson (2023) documented middle-aged womenâs experiences and found that diagnosis, when it finally arrived, reframed entire lives.
Crowson et al. (2023) used a co-produced Delphi study to identify post-diagnostic support priorities for autistic adults in the UK. The priorities that emerged â understanding yourself, navigating systems, connecting with community â are straightforward. The fact that they needed a formal study to identify them says something about how far current services are from meeting basic needs.
The system design problem
The current diagnostic model treats autism assessment as a specialist clinical act performed by a small number of trained professionals. Demand has grown exponentially as awareness has increased, but the workforce has not grown to match. The result: a bottleneck that no amount of efficiency improvement can resolve within the existing model.
NAITâs pathfinder work in Scotland (2022â2023) tested an alternative: a stepped-care model across four pilot sites (Fife, Borders, Lanarkshire, Highland). The model broadened the workforce involved in assessment beyond psychiatrists to include allied health professionals, nurses, and third-sector partners. It introduced support before, during, and after diagnosis rather than treating diagnosis as a gateway that must be passed before any help is available. It recommended unified pathways for autism and ADHD, recognising that co-occurrence is the norm rather than the exception.
The pathfinder findings were practical: multi-disciplinary teams work, support should not be diagnosis-dependent, and the current mental health team model cannot absorb neurodevelopmental assessment on top of everything else it is expected to do. NAIT recommended that every Health and Social Care Partnership in Scotland establish an adult neurodevelopmental pathway strategy group and action plan.
By 2025, progress had been uneven. Some areas had implemented elements of the model. Others had gone backwards. The Royal College of Psychiatrists declared the situation a âcrisis pointâ in October 2025, and the Scottish Government announced a cross-sector taskforce with ÂŁ500,000 in additional funding in June 2025. Whether this is proportionate to a waiting list of 65,000 people (42,000 children, 23,000 adults) is an open question.
The European policy landscape
Precious (2020) analysed Western European autism policies using a typology of political empowerment: does the government treat autistic people as needing to be informed (educated by experts), involved (consulted in policy), or empowered (co-governing)? England, Wales, and Denmark scored highest for empowerment. Traditional groupings didnât hold â the UK split across categories, and Spain departed from its Southern European counterparts. The analysis reveals that the political position a government takes on autistic peopleâs capacity shapes the services it designs.
At the European level, coordination remains aspirational. The European Commission committed in September 2024 to a âcommon approach to autism.â A high-level conference in April 2025 brought together researchers, Autism Europe, and the European Parliamentâs Disability Intergroup. The UN Committee on the Rights of Persons with Disabilities called for mandatory autism training for professionals and quality support services for independent living. Whether commitments translate into funded action remains to be seen.
Neuro-affirming practice
NAITâs 2024 guidance on neuro-affirming diagnostic reports represents a quiet shift in how diagnosis is communicated. The guidance, co-produced with neurodivergent people, addresses a specific harm: diagnostic reports that read like character assessments, written in deficit language, listing what the person cannot do. Some recipients described reading their reports as a âcharacter assassination.â
The guidance recommends: make the diagnosis decision clear, use neuro-affirming language, address what neurodivergent people actually want from a report (self-understanding, practical guidance, validation), and include individualised support recommendations. It is a practical document that translates neurodiversity principles into clinical writing. It also reveals how far standard practice still has to travel â the fact that âdonât write reports that make people feel terrible about themselvesâ needs formal guidance tells its own story.
Open questions
Can the diagnostic bottleneck be resolved within existing healthcare structures, or does neurodevelopmental assessment need to move substantially outside the clinical model? The NAIT pathfinder work suggests the latter, but implementation at scale has not been achieved.
What happens to the people who are waiting? The five-year wait is not neutral time â it is time spent without accommodations, without self-understanding, without access to medication (for ADHD), without community. The cost of waiting is borne entirely by the individual.
How should diagnostic services handle the intersection of neurodivergence with migration, ethnicity, and language? Kawa et al. (2017) and Morinaga (2020) found that immigrant and ethnic minority populations in Europe face additional barriers to identification, driven by clinician bias, cultural factors, and systemic exclusion.
Key sources
- NAIT (2023). Waiting times for neurodevelopmental assessment in Scotland for adults.
- NAIT (2023). Adult Neurodevelopmental Pathways: Pathfinder Sites Report.
- NAIT (2024). Neuro-affirming reports: guidance for practitioners.
- Radev, S., Freeth, M., & Thompson, A.R. (2024). How healthcare systems are experienced by autistic adults in the UK: A meta-ethnography. Autism.
- Mendez, M.A. et al. (2023). Autism care pathway in Europe. European Psychiatry, 66(1).
- Precious, K. (2020). Informed, involved, or empowered? Three ideal types of autism policy design in Western Europe. European Policy Analysis, 7, 185â206.
- Hayes, J. et al. (2021). âNot at the diagnosis pointâ: Dealing with contradiction in autism assessment teams.
- Crowson, R. et al. (2023). Post-diagnostic support priorities of autistic adults in the UK. Co-produced Delphi study.
- Harmens, M. et al. (2022). Autistic womenâs diagnostic experiences: Interactions with identity.
- Royal College of Psychiatrists Scotland (2025). ADHD and autism waiting lists hit crisis point.
- SPICe (2025). Neurodevelopmental pathways and waiting times in Scotland.