Why up to 97% of autistic women over 40 go undiagnosed
Autism in women is missed on a scale that’s hard to overstate. A King’s College London review found that between 89% and 97% of autistic adults over 40 in the UK remain undiagnosed, and because women are diagnosed later and in far smaller numbers than men, the real figure for women sits at the sharper end of that range.
If you’re reading this because you’re wondering whether that’s you, you’re not being dramatic and you’re not late to something you should have caught sooner. The system was built around how autism shows up in boys, and it’s still catching up.
Key takeaways
- Community-based studies estimate the male-to-female autism diagnosis ratio at roughly 3:1, not because autism is rarer in women, but because it’s recognised less.
- As of March 2026, over 270,000 people in England had an open referral for suspected autism, and around 9 in 10 had already waited longer than NICE’s recommended 13 weeks.
- Masking, being misdiagnosed with anxiety, an eating disorder, or a personality disorder first, and clinicians relying on outdated male-presentation checklists are the three most cited reasons women are missed.
- A formal diagnosis is not a requirement for starting therapy. Counselling support can begin while you’re waiting, self-identifying, or still deciding whether to pursue assessment at all.
- Right to Choose and private routes can be faster than a standard NHS pathway, but cost and postcode both affect what’s actually available to you.
Why is autism missed in women for so long?
Autism is missed in women mainly because the diagnostic criteria were built from research on boys, and girls and women learn to mask their traits early, often without realising that’s what they’re doing. Masking means consciously or unconsciously copying the people around you, rehearsing conversations, suppressing stimming, forcing eye contact, so you pass as neurotypical. It’s exhausting, and it works well enough that teachers, GPs, and even parents miss the underlying picture.
On top of that, a 2025 meta-synthesis in BJPsych Open pointed to environmental mismatch as a key driver, meaning the problem sits in institutions not built for autistic students, rather than in the individual. Add to this that autistic women are frequently referred toward mental health services for anxiety or eating disorders rather than toward autism assessment, and misdiagnosed with personality disorders along the way, and you get decades where the actual cause of a lifetime of “why do I find this so much harder than everyone else seems to” goes unnamed.
None of this is a character flaw or a failure to notice something obvious about yourself. It’s a system that wasn’t designed to see you.
Book a free 20-minute consultation with me here if you want to talk any of this through before deciding what your next step is, whether that’s assessment, counselling, or just working out what you’re even looking for.
What does the current NHS waiting list actually look like?
As of March 2026, NHS data showed over 270,000 people in England with an open referral for suspected autism, and roughly 90% of them had already waited past NICE’s 13-week guideline. In some areas, the reported average wait is now over a year, and some services have quoted waits of several years for a full diagnostic assessment. This isn’t a reflection of how urgent or valid your situation is. It’s a reflection of a diagnostic system that hasn’t scaled with demand.
The table below sets out the main routes people use, so you can see roughly what each involves before choosing one.
| Route | Typical wait | Approx. cost | Notes |
|---|---|---|---|
| Standard NHS referral (via GP) | Often 12+ months, sometimes several years depending on area | Free at point of use | NICE guideline is 13 weeks; in practice most people wait far longer |
| NHS Right to Choose | Varies by provider, sometimes weeks to a few months for initial appointment | Free at point of use | Lets you choose an approved provider outside your local trust; ask your GP to refer this way |
| Private assessment | Weeks to a few months | Several hundred to over a thousand pounds | Faster, but self-funded; check the clinician is qualified to NHS-recognised standards |
| Self-identification without formal diagnosis | No wait | Free | A valid starting point; many people begin here and decide later whether to pursue formal assessment |
Whichever route you’re on, or even if you’ve chosen not to pursue formal diagnosis at all, you don’t have to wait for a letter to start making sense of your experience in counselling.
Do I need a formal diagnosis to get support?
No, you don’t need a formal diagnosis to start counselling or to describe yourself as autistic. Many of the women I work with come in already fairly sure, sometimes after years of research, self-tests, and recognising themselves in other women’s accounts, and use counselling to process what that means rather than to get a label confirmed. Others are on an NHS waiting list and want somewhere to think out loud while they wait. Both are completely valid reasons to start.
What I offer as a neurodivergent-affirming, integrative counsellor is space to work through identity questions, masking and burnout, and the practical day-to-day struggles, without needing a diagnosis first to make your experience count.
What does it feel like to be diagnosed later in life?
For most women, a late autism diagnosis brings relief first, and then grief. The relief is usually about finally having language for a lifetime of feeling like you were doing everything slightly wrong, working twice as hard to seem fine. The grief tends to arrive a bit later, once the relief settles, and it’s often about the years spent masking, the relationships that didn’t work because you were performing rather than being yourself, or the support you could have had earlier.
Both feelings are normal, and neither cancels the other out. If you want more detail on this, I’ve written separately about how it feels to be diagnosed later in life.
Why do women get diagnosed with autism later than men?
Women get diagnosed later than men largely because of the 3:1 male-to-female diagnosis ratio found in community studies, a gap researchers now attribute to recognition rather than actual prevalence. Autism assessment tools were developed and validated on predominantly male samples, so traits that present differently in women, like more subtle or socially-scripted special interests, or internalised rather than externalised distress, are more easily missed by clinicians working from those tools.
I’ve gone into this in more depth in a separate post on why women get diagnosed with autism later, if you want the fuller picture.
What if I think I’m autistic but haven’t been assessed?
If you think you’re autistic but haven’t been assessed, the most useful next step is usually to get curious rather than to rush toward a formal process, whether that’s reading up on the female autism phenotype, connecting with other late-identified women, or talking it through with a therapist who won’t need convincing that your experience is real. I’ve written a dedicated post on what to do if you think you’re autistic that walks through the options in more detail, including how NHS and Right to Choose referrals actually work.
If part of what’s coming up for you is also about sexuality or identity, and you’re queer or questioning alongside all this, it’s worth knowing that a queer-safe therapeutic space is genuinely rare, and I’d always recommend working with an LGBTQIA+ affirming therapist if coming out is part of what you’re carrying right now. I offer that alongside neurodivergent-affirming practice, because for a lot of my clients the two are tangled together.
Frequently asked questions
Is autism actually more common in women than we think, or is diagnosis just improving?
Both are likely true. Autism prevalence in women hasn’t changed, but recognition has, as clinicians and researchers move away from diagnostic tools built almost entirely on male presentations. The 3:1 diagnosis ratio reflects who gets identified, not necessarily who’s autistic.
How long does an NHS autism assessment take in 2026?
As of March 2026, roughly 90% of the 270,000+ people on an open referral in England had already waited past NICE’s 13-week guideline, with real-world waits commonly running well over a year depending on your area and local trust.
Can I get autism support before I have a diagnosis?
Yes. Counselling, peer communities, and workplace adjustments can all be accessed without a formal diagnosis, and many people find creative and psychoeducational approaches genuinely useful while they wait or while they decide whether to pursue assessment at all.
What’s the difference between NHS Right to Choose and a standard NHS referral?
Right to Choose lets you ask your GP to refer you to any NHS-approved provider in England rather than only your local trust, which can sometimes mean a shorter wait, though this varies a lot by provider and demand.
Do I have to identify as autistic to relate to this?
No. Plenty of women read posts like this one out of curiosity rather than certainty, and that’s a completely reasonable place to start.
This post is for general information and isn’t a substitute for a clinical diagnosis or medical advice. If any of this resonates and you want to talk it through, you can find out more about my practice or get in touch. I also have a free meditation workbook if you’d like somewhere gentle to start.
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