What's the harm in a diagnosis?

Our Autism Champion, Dr Conor Davidson, considers the advantages and disadvantages of giving an autism diagnosis.

I’ve spent pretty much my whole career trying to persuade colleagues in general adult psychiatry to take autism seriously. So the idea that autism could be overdiagnosed causes me some cognitive dissonance to say the least. Yet the question of possible overdiagnosis has become impossible to ignore as the demand for autism assessment continues to steadily increase.

Recently, there has been another flurry of media interest, prompted by the release of Dr Suzanne O’Sullivan’s new book, The Age of Diagnosis: sickness, health and why medicine has gone too far. In it, O’Sullivan argues that everyday variation in human experience is being over-medicalised and inappropriately given diagnostic labels like autism and ADHD.

Autism on the rise?

Over the last few years, I’ve spoken about this to many colleagues who work in the field of neurodevelopmental psychiatry. They hold a range of views, all sincerely held in good faith. Many argue that the rise in diagnosis is unequivocally a good thing, correcting past decades of widespread underdiagnosis (and indeed, misdiagnosis). Some, however, express concern over the direction of travel: are we heading the same way as the USA, where 1 in 36 children now have an autism diagnosis?

There is no question that autism diagnosis is on the increase. There was an exponential 787% rise in recorded autism diagnoses in the UK between 1998 and 2018. The latest NHS England data shows 5.9% of boys and over 2% of girls aged between 10-13 years old have autism. This is much higher than the oft-quoted national prevalence figure of 1.1%.

Of course, autism prevalence is much more complicated than these headline figures suggest. Autism is massively under-recognised in older people. In psychiatric settings, it is commonly missed, perhaps due to overshadowing by co-occurring mental illness. And there is widespread consensus within the clinical community that historically, we have tended to underdiagnose autism in girls and women.

'What's the harm in giving a diagnosis?'

The 1.1% prevalence figure comes from the Adult Psychiatric Morbidity Survey (APMS) and is ten years old. Since then, the ICD-11 has been published, which allows greater consideration of change in autism presentation over time and the impact of masking and camouflaging (both of which are more marked in females). The APMS is due to publish updated results later this year; it will be interesting to see if the autism prevalence (particularly in females) has increased.

Even if O’Sullivan is right, and ‘milder’ forms of human social difficulty are now given the label of autism, is this necessarily a bad thing? I thought about this recently when, in the adult autism clinic where I work, we were considering whether a patient met the diagnostic criteria. It was a scenario no doubt familiar to many neurodevelopmental clinicians: the patient described a number of autistic traits, but the developmental history was not particularly suggestive and the ADOS score was in the ‘autism spectrum’ range. The multidisciplinary team were debating whether all the DSM-5 criteria were met, and to what extent masking was a factor explaining the lower-than-expected ADOS score. A junior doctor was there, in her first week in post, and asked us: ‘What’s the harm in just giving a diagnosis?’.

It was a great question. The patient, like many we see in clinic, was already invested in an autistic identity and saw it as an explanation for their struggles with social anxiety and workplace difficulties. When diagnosed with autism, most people are relieved and grateful. At follow-up, they usually describe a psychological benefit in terms of self-understanding and self-acceptance.

A diagnosis can unlock reasonable adjustments in the workplace. It allows access to autism-specific charities and support groups. It also provides a sense of identity and connection to the wider autistic community. For psychiatric patients, we have found that an autism diagnosis can provide a new ‘lens’ to reformulate mental health difficulties and lead to highly beneficial treatment avenues and adaptations.

Potential downsides of a diagnosis

It would be surprising if these very positive impacts of an autism diagnosis did not exert an unconscious pressure on clinicians, when faced with ambiguous cases, to err towards making a diagnosis. However, I think it is important for us as a clinical community to also reflect honestly on the potential downsides of an autism diagnosis.

There is not much research evidence to guide us in this. Qualitative studies suggest that for some people, the emotional and psychological impact of a diagnosis can be negative, at least in the early stages, triggering feelings of confusion, shock or regret. Disclosure of diagnosis can be tricky to navigate – some people report being disbelieved by family members or not taken seriously by employers. There can also be implications for insurance, travel visas to certain countries, and career options (for example, joining the military).

As a psychiatrist, a particular concern for me is whether a diagnosis can, in some cases, actually lead to worse rather than improved functional and mental health outcomes. O’Sullivan reports that in interviews with people diagnosed with autism and ADHD, she noticed: ‘all perceived their lives to be better off thanks to a diagnosis. Every person welcomed the diagnosis into their lives. But almost all had left their job, dropped out of education and lost many old friends. Several were housebound…I saw a worrying gap between the perceived benefit of being diagnosed and any actual improvements in quality of life.’

Leaving aside the fact that this is anecdotal rather than research evidence, an alternative interpretation could be that these people had adjusted their lifestyle to better fit their neurodivergent identity, and to take them at their word that their quality of life is better. That said, given what we know about the long-term mental health impacts of unemployment and social isolation, it would be concerning if an autism diagnosis was associated with such outcomes. It is at least theoretically possible that an autism diagnosis may lead to greater avoidance of social activities and thus worsen levels of social anxiety in the long run.

Ongoing research is essential

My own clinical experience is that the sort of negative functional outcomes that O’Sullivan describes are rare. However, I don’t think we can simply dismiss concerns like these. Our clinical practice must be guided by evidence. Further research is required to systematically investigate the medium and long-term impact of autism diagnosis on quality of life. 

Ultimately, the question of whether autism is being overdiagnosed—and the potential harms or benefits—is complex and nuanced. While diagnosis can offer validation, support, and access to resources, it is crucial that we remain mindful of possible unintended consequences. A well-intentioned diagnosis should empower individuals, not inadvertently limit their opportunities. As clinicians, researchers, and advocates, our responsibility is to ensure that diagnostic practices are rooted in robust evidence, ethical integrity, and a genuine commitment to improving lives. This is why ongoing research is essential—so that we can better understand the real-world impact of diagnosis and continue to refine our approach in the best interests of those we seek to help.