TopicsBehaviourNow it makes sense: ADHD and Autism in adulthood

Now it makes sense: ADHD and Autism in adulthood

Growing numbers of adults are being diagnosed with autism or ADHD. Journalist Anna Scott asks, what’s the impact and how can you help?

It was during the making of a documentary, Our family and autism, broadcast in December 2021 that the model and TV personality Christine McGuinness was diagnosed with autism (BBC, 2021). She and her husband, TV presenter Paddy McGuinness – whose three children are autistic – completed autism spectrum quotient tests and Christine was subsequently diagnosed by a specialist.

‘To actually be told that I am autistic just made everything fall into place. I realised that basically what I’d been doing my whole life was acting. It’s exhausting trying to juggle everything. I was extremely emotional, but relieved,’ she said (BBC, 2021).

Similarly, the comedian Rory Bremner was diagnosed with attention deficit hyperactivity disorder (ADHD) as an adult after he recognised symptoms in a diagnosed relative. He describes the condition as both his ‘best friend and worst enemy’ (Channel 5 News, 2022).

Both these cases in the public eye in fact reflect a growing trend for these conditions typically diagnosed in childhood to be discovered in adulthood. This has a lot to do with greater understanding and awareness of autism and ADHD.

Prevalence rates for autism and ADHD in the population have grown dramatically in recent years (see Autism and ADHD in figures overleaf). ‘We now know that at least 1% of the population is autistic, and at least 2% to 3% of the population is ADHD,’ says Dr Fiona Gullon-Scott, lecturer in clinical psychology at Newcastle University.

‘As our understanding of neurodiversity has changed and improved over the last decade or so, so has wider awareness, and adults who may have struggled throughout their lives for various reasons might now realise that this might be the result of an undiagnosed neurodivergent presentation,’ she adds.

Greater awareness

ADHD has been hugely underdiagnosed or even misdiagnosed, in part because of the understanding now that it’s a disorder that continues throughout the lifespan and can get worse for adults as they become more independent and manage different aspects of life, according to Dr Sally Cubbin, a consultant psychiatrist in Oxford with expertise in the diagnosis and management of adult ADHD. ‘It’s still hugely under-recognised in psychiatric services,’ she says.

People might visit their GP with mental health problems and complain of anxiety, mood swings or being overwhelmed, and ‘actually it’s the ADHD driving those symptoms, but they are diagnosed with something else like anxiety or depression. So often it’s the patient that might have a child with ADHD and think, “Actually, I am just like my child.”’

Increased media coverage has raised awareness of developmental conditions such as ADHD and autism among the general public, across health and social care and educational settings, and workplaces, says London-based Dr Quinton Deeley, a consultant psychiatrist specialising in autism, ADHD, learning disability and acquired brain injury in adults. ‘There are more people who feel confident to be able to make a diagnosis or to identify somebody as requiring diagnosis, and those services have expanded,’ Quinton adds.

It’s very difficult to pinpoint, however, where there is a true increase in diagnoses epidemiologically, ‘because the only way you could really do that would be to apply the same diagnostic criteria using fairly strict sampling methods over a long period of time’, says Quinton. ‘Even then, that could potentially be compounded because the population changes, the age structure of the population changes and the demographics of the population change. In practice, the increased recognition is due to raised awareness across the board at every level, with increases in training and resources available for diagnosis.’

There’s also now greater understanding of how adults present in cases of autism or ADHD, particularly in relation to autistic women masking symptoms by mimicking neurotypical behaviours, such as forcing themselves to make eye contact or disguising  self-stimulating behaviour, or ‘stimming’, such as a jiggling foot. ‘There may be differences in how the condition manifests in women, which leads to underdetection,’ explains Quinton. ‘There is some evidence that suggests women tend to score lower on social communication difficulties than men do.’

Dr Tony Lloyd, CEO of the ADHD Foundation, says the charity is aware that there are almost as many diagnoses of the condition in adults as children now, and half of those adults are women. ‘We’re beginning to move away from stigma and ignorance,’ he says. ‘We also know that women who have got ADHD but [it’s] not identified [are] significantly more likely to experience anxiety and depression and they’re given antidepressants or often misdiagnosed.’

There is now also greater understanding of the other conditions that present with ADHD and autism, such as dyslexia, dyspraxia, immune disorders and inflammatory diseases.

Joining up the pieces

So there are many ways that a diagnosis can help an adult, not least understanding themselves better, focusing on their strengths and getting support. ‘Most people I know of who have been diagnosed have been relieved as it helps them to understand themselves,’ says Dr Jackie Applebee, GP and chair of Doctors in Unite.

Tom Purser, head of volunteering, guidance and campaigns at the National Autistic Society, agrees: ‘A diagnosis can be life-changing and vital to getting timely care and support. Many autistic adults find that a diagnosis in later life explains things about themselves and how they’ve experienced the world since they were children.

There are almost as many diagnoses of the condition in adults as children now, and half of those adults are women

When might diagnoses happen? ‘We sometimes hear stories of people who realise they’re autistic after someone close to them receives a diagnosis,’ says Tom. ‘This comes from seeing similar traits in themselves, for instance an over or under-sensitivity to light, sound or touch, challenges around communication and highly focused interests.’

Understanding why some things are difficult for a person means understanding how their brain processes information, and how they see and experience the world, according to Fiona. ‘For example, we know that the sensory world is very different for an autistic person and that things which my brain might ignore or filter out might be something which the autistic person finds invasive, distressing or overwhelming,’ she says.

‘So when an autistic person is screaming or trying anything they can to avoid a room with fluorescent lighting, I know that it would be utterly wrong to try behavioural techniques that try to make that person tolerate that environment. The environment is causing their sensory system physical pain. They cannot change how their brain processes information, so no amount of behavioural intervention will make their brain less sensitive,’ she adds.

For a condition like ADHD, which can be treated with medication, a diagnosis can be life-changing. ‘In terms of what actually changes the symptoms and makes people feel less restless, less distracted, more able to concentrate, it’s the medication – methylphenidate, known as Ritalin or Concerta, most often – and it’s very effective, probably more effective than any psychiatric drug,’ says Sally. ‘At least to a degree and they feel they can concentrate. They’re less distractible and less restless. And that makes a huge difference in your ability to perform in life.’

Not to mention that ‘untreated ADHD has very high comorbidity, with coexisting mental health conditions’, explains Quinton. ‘So very high levels of anxiety disorder, depression, substance misuse problems, relationship problems, financial problems, debt, gambling, and so on.’

A Downside of discovery?

However, not everyone wants a diagnosis later in life, according to Professor Amanda Kirby, CEO of neurodiversity consultancy Do-IT Solutions. ‘Some people prefer to gain strategies to help them but not be defined by one diagnosis,’ she explains, adding that because neurodivergent traits often co-occur, no single label ‘fully represents who someone is and may be the diagnosis they can access or is available’.

Concerns about the stigma surrounding certain conditions can put people off seeking a diagnosis – they may worry about telling their employer for fear of missing out on promotions, for example, says Sally. And an ADHD diagnosis can have an impact on driving and car insurance premiums. ‘There is a higher accident rate and people should tell the DVLA if they have an ADHD diagnosis,’ she says.

But generally speaking, a diagnosis of ADHD or autism is welcome for adults. ‘I have been researching, teaching and doing clinical work in the field for 30 years now, and to date my experience has been that diagnosis has predominantly been positive for people,’ says Fiona. ‘That doesn’t mean that it isn’t hard to process or come to terms with.’

She says that for many adults who have spent a lifetime trying to cope and adjust and adapt, but without awareness or recognition of their autism or ADHD, it can lead to a period of having to adjust to finally understanding themselves, especially if they have low self-esteem and a ‘lifetime of being told, both implied and overtly, that they are “wrong” or “broken”, “naughty” or “bad” or “failing” somehow’.

She adds: ‘To finally be told that the difficulties they have experienced are not their fault, that they are not broken, instead that they have different minds and process differently, and to then be able to find a community with whom they can identify – all of that is hugely positive and can be extremely validating.’

‘to be told that they are not broken, that they have different minds and process differently – all of that is hugely positive and extremely validating’

Nor is it ever ‘too late’ for a diagnosis. Quinton assessed a man in his late 70s for ADHD, who felt he had some of the symptoms and thought a diagnosis would make sense of his life. ‘He wasn’t seeking treatment. He was he was just trying to understand himself,’ he says. And for autism? ‘My experience of working with people with autism over the years is that it has very rarely been the case that somebody has not been helped by receiving a diagnosis of autism in the sense that they have not understood themselves better.’

What’s your role?

Since both ADHD and autism often have a genetic component (Faraone and Larsson, 2019; Bai, et al, 2019), when a community practitioner (CP) looks after a child with one of these conditions, it’s worth considering a suggestion to parents that they think about being screened, advise Lucy and Quinton.

‘[A diagnosis of ADHD] can be because of prematurity, low birth weight, but almost always it’s in the genes,’ says Lucy. ‘It may be causing parents an awful lot of impairment and the treatment is really effective.’

CPs can also play a role in signposting and encouraging people to see their GP as a  first step, or to take medication if they are diagnosed with ADHD. Support once diagnosed can also come in the form of coaching people to deal with organisational aspects of their life, or decisiveness if they struggle to make decisions, for example.

The charities offer guidance on getting diagnosed as an adult (see Resources, plus Definitions and How can adults get a diagnosis?).

Just one way of seeing

Amanda says CPs should be person-centred and have access to evidence-based and practical information to be able to share, as well as knowing what is available locally for support, such as adult services and support groups. ‘[They should also] understand about overlap across conditions and see that neurodiversity is about differences not only in developmental conditions but relates to acquired conditions where there is a change in cognition,’ she adds.

But the fact that mental health services are severely underfunded and specialised support ‘barely exists’ makes things difficult, says Jackie. ‘If CPs have the time and resources they can be a great support but [as they’ll be well aware of themselves] too often they are spread too thin,’ she says.

What remains important is understanding. As Fiona says: ‘If there is one thing that I would want healthcare practitioners to do it is to show empathy, to listen, to hold in mind that our (neurotypical) view of the world is just one way of experiencing the world.’


Attention-deficit hyperactivity disorder (ADHD) A condition, also known as attention deficit disorder (ADD), that affects people’s behaviour so that they appear restless, have trouble concentrating and may act on impulse (NHS, 2022).

Autism or autism spectrum disorder (ASD)

A lifelong developmental disorder that affects how people communicate and interact with the world, and impacts their sensitivity to light, sound, taste or touch (National Autistic Society, 2022a).


The concept that people experience and interact with the world around them in many different ways, applying to those with ASD, ADHD, dyslexia, dyspraxia and a number of other conditions (Baumer and Frueh, 2021).


A term used for people without conditions such as ASD and ADHD.

How can adults get a diagnosis?

  • Advice for adults seeking diagnosis includes being as informed as possible before a GP appointment, such as being ready to explain the reasons why they think they may have ADHD or autism, and discussing their experience as a child or adolescent, and the impact on their life (see Resources for more).
  • As the National Autistic Society state, a GP will need a reason to then refer someone on for the diagnosis by a specialist.
  • For autism, most adults see a psychiatrist, clinical psychologist or a team made up of people from different professions for their diagnosis (NAS, 2022b).
  • Adults with ADHD may be referred to an adult psychiatrist or an appropriate qualified healthcare professional with training and expertise in the diagnosis of ADHD (NHS, 2022), such as a clinical psychologist.

What about other health issues? Sickle cell disease

Autism and ADHD are not the only long-term disorders typically diagnosed in childhood, that can be missed. Every baby born in the UK is now screened for sickle cell disease. However, some adults who have migrated to the UK from countries without a programme may not realise they have the condition until later in life, according to John James, CEO of the Sickle Cell Society. ‘I knew a lady of the Windrush generation who came over to the UK in the 1950s and she was diagnosed with sickle cell when she was having her first child,’ he says.

However, there are ‘significant failures of care’ in helping people with sickle cell, John says. He cites the case of Evan Nathan Smith, the 21-year-old Londoner with sickle cell who died in 2019 after being refused oxygen on a hospital ward (Leigh Day, 2021).

‘I think the first thing [for CPs] is to have an understanding of the impact of sickle cell and making sure [those with the illness] know how they can access specialist support and advice,’ John says.



Bai D, Yip BHK, Windham GC et al. (2019) Association of genetic and environmental factors with autism in a 5-country cohort. JAMA Psychiatry 76(10): 1035-043.

Baumer M, Frueh J. (2021) What is neurodiversity?. Harvard Health Publishing. See: (accessed 5 April 2022).

BBC. (2021) Christine McGuinness – How my autism can help me to help my kids. See: (accessed 5 April 2022).

5 News. (2022) Mind Matters: Comedian Rory Bremner on living with ADHD. See: (accessed 5 April 2022).

Faraone SV, Larsson H. (2019) Genetics of attention deficit hyperactivity disorder. Molecular Psychiatry 24(4): 562–75.

Leigh Day. (2021) Inquest finds failure to appreciate sickle cell crisis symptoms in the death of 21-year-old Evan Nathan Smith. See: (accessed 5 April 2022).

National Autistic Society. (2022a) What is autism?. See: (accessed 5 April 2022).

National Autistic Society. (2022b) Diagnostic assessment – a guide for adults who think they might be autistic. See: (accessed 5 April 2022).

NHS. (2022) Overview: Attention Deficit Hyperactivity Disorder (ADHD). See: (accessed 5 April 2022).

Russell G, Stapley S, Newlove-Delgado TN et al. (2021) Time trends in autism diagnosis over 20 years: a UK population-based cohort study. Journal of Child Psychology and Psychiatry (online only) See: DOI: 10.1111/jcpp.13505.

Sickle Cell Society. (2021) No one’s listening: an inquiry into the avoidable deaths and failures of care for sickle cell patients in secondary care. See: (accessed 5 April 2022).

Song P, Zha M, Yang Q et al. (2021) The prevalence of adult attention-deficit hyperactivity disorder: A global systematic review and meta-analysis. Journal of Global Health 11: 04009.

Youssef A. (2021) Getting diagnosed with ADHD when you’re an adult. ITV. See: (accessed 5 April 2022).

Image credit | Shutterstock

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