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The problem isn’t a diagnosis the problem is undiagnosed ADHD in Adults & Autism

neurodiversity and diagnosis words with different brain pictures

Let’s start this blog post off with some facts (because I always come through with the evidence-based stuff)

The Lancet published an article stating that,

“Out of a population of 56.5 million [in England]; we estimate that 463,500 (0.82% of the population) have been diagnosed autistic, and between 435,700 and 1,197,300 (58.63–72.11% of autistic people; 0.77%–2.12% of the English population) may be autistic but undiagnosed as of 2018.”

So that shows us that nearly the same number of people again if not double, are undiagnosed Autistic.

Their findings also found that there remains a substantial diagnostic gap in adults compared to children and young people in England. 

Why is there a diagnostic gap in adults?

It can be due to a lack of awareness and understanding of autism in adults by healthcare/medical professionals, by adults themselves, a lack of access to services, the stigma that still surrounds Autism, wait times of receiving a diagnosis and more… (feel free to comment below if you suspect you are Autistic but are undiagnosed)

What does this mean for undiagnosed Autistic people?

It means that Autistic adults and their needs are NOT being recognised or met! Which means that many adults are not living as fulfilling a life as possible due to a lack of support for their challenges that come with being neurodivergent. 

How about with undiagnosed ADHD in adults (Attention Deficit Hyperactivity Disorder)?

Similarly to Autism there is a pattern of underdiagnosis specifically undiagnosed ADHD in adults, has also been reported. 

Why Is There Underdiagnosis in ADHD?

A report found that due to ‘cultural and structural barriers operating at all levels of the healthcare system’ that there is a de-prioritisation of ADHD as a result. 

The services for ADHD diagnosis are absolutely insufficient with a report suggesting waiting times of up to five years for an adult ADHD assessment in the UK.

There is a huge stigma surrounding ADHD that it is a medicalised social construct.

What does this mean for undiagnosed ADHD people?

Dr Peter Carpenter, Chair of the Royal College of Psychiatrists’ Neurodevelopmental Special Interest Group, said: 

“People with ADHD can struggle with significant disruption to their personal and professional lives if the condition is left untreated. It’s good to see public awareness of the disorder has grown and that more people are coming forward for a diagnostic assessment and treatment.

“Once someone has a diagnosis, they usually benefit from adjustments at work or in other areas of their daily lives. Medication can help treat symptoms of inattention, hyperactivity and impulsivity, particularly in those who have a moderate to severe expression of ADHD. Talking therapies and peer support groups can also be beneficial.”

So you see, with just looking at Autism and ADHD, the problem with undiagnosis. If I covered all neurodivergencies in one blog we would be here for a very long time!

You must learn (or remember) that you do NOT have to be diagnosed to advocate for yourself and put tools in place to support your challenges, if you suspect that you are neurodivergent. The main reason to seek a diagnosis is that it can open up access to some services aswell as medication for ADHD.

If I can help any further with this topic please get in touch.

Thank you for reading. Please do comment and share if you feel this was helpful for you.



Elizabeth Onions et al. (2023). Autism in England: assessing underdiagnosis in a population-based cohort study of prospectively collected primary care data. The Lancet Regional Health Europe, Volume 29, DOI:

Susan Young et al. (2021). Failure of Healthcare Provision for Attention-Deficit/Hyperactivity Disorder in the United Kingdom: A Consensus Statement. Frontiers in Psychiatry, Volume 12, doi: 10.3389/fpsyt.2021.649399

Significant rise in ADHD diagnoses in the UK. (2023). UCL News. Cited on 12th January 2023,

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