Symposium: Are we over-diagnosing mental health conditions?

New Statesman​

22-05-2025

Clockwise from top left: Lade Smith, Suzanne O'Sullivan, Minesh Patel, Joanna Moncrieff, Brian Dow
Britain is in the grip of a mental health reckoning. Once taboo, the language of anxiety, depression, trauma and neurodivergence is now part of everyday conversation. Public campaigns have encouraged us to speak openly about mental well-being. But as awareness has surged, so too has a thornier question: are we diagnosing too much, too readily?
In March, Health Secretary Wes Streeting argued that we are. 'Not every feeling of sadness is depression, not every feeling of worry is anxiety,' he said, warning that Britain is at risk of 'over-diagnosing' mental health conditions, especially in young people. His comments sparked fierce debate. Is the surge in diagnoses a long-overdue recognition of hidden suffering? Or are we at risk of medicalising life's ordinary struggles?
The numbers are striking. Demand for NHS mental health services has more than doubled since 2017. Yet questions are growing over whether those services – already overwhelmed – are being diverted from those in greatest need. Are we mistaking everyday emotions for clinical disorders? Or does broader diagnosis simply reflect how far we've come in confronting mental illness?
This is not just a clinical debate – it is a political one. The way we define and diagnose mental illness shapes the policies and resources that follow: whether that's school counselling budgets, workplace well-being schemes, GP referral pathways, or access to talking therapies. Over-diagnosis risks diluting resources and excessive medicalisation; under-diagnosing leaves silent suffering unaddressed. While one finds a range of views, even among our experts, there is one clear consensus: the system itself is in dire need of support.
Dr Lade Smith CBE, President, Royal College of Psychiatrists
It is no surprise that there has been an increase in mental illness diagnoses. Risk factors associated with mental ill-health – financial, housing and food insecurity, loneliness and isolation – have increased over the past decade.
We have seen a 20 per cent increase in the number of people classified as disabled because of anxiety and depression – both eminently treatable conditions, both driven by social determinants.
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With earlier intervention and assertive treatment, anxiety and depression can get better within months – long before a person's condition deteriorates into disability. However, the number of people waiting for mental healthcare has grown by 29 per cent in the last two years and now stands at 1.6 million.
Moreover, severe mental illnesses, such as bipolar disorder and schizophrenia, are under-diagnosed or diagnosed far too late. This is particularly important for younger people, because 75 per cent of all mental health conditions arise before the age of 24.
With illnesses like bipolar disorder or schizophrenia, it can take up to ten years before people receive a diagnosis and treatment, significantly impacting them achieving their potential.
During this time of no diagnosis, their illness is likely to curtail their ability to complete education, function at work and form healthy relationships. They may even become homeless or come into contact with the criminal justice system.
It is essential that people with mental illness have access to an evidence-based comprehensive assessment from a trained psychiatrist or qualified mental health professional, which formulates their problem, clarifies their diagnosis and provides a package of care and treatment to enable that person to recover and have the best quality of life they can.
When misdiagnosis does occur, it is largely driven by people being left to diagnose themselves or being assessed by those with no or inadequate specialist skills and training. We must be careful not to encourage stigma and discrimination. People with mental illness are not 'fake sick'; the UK's productivity has not been undermined by over-diagnosis, but by poor access to timely and effective care.
The Darzi investigation noted that mental illness is 20 per cent of the disease burden in the UK but receives 10 per cent of health funding. The treatment gap created by chronic under-resourcing results in a failure to quickly ascertain who is ill and who is not, and to assertively treat those who actually need it.
Over-diagnosis is far less of an issue than lack of access to good-quality timely assessment and treatment by well-qualified mental health staff.
Dr Suzanne O'Sullivan, Consultant neurologist, University College London
Any discussion about over-diagnosis needs to start with a clarification of the meaning of the term. Over-diagnosis should never be read to imply a person is not struggling or in need of support. It simply asks if medicalising that suffering is the best way forward for them.
Mental health conditions don't come with biological markers, so nobody can truly identify the point at which psychological distress moves from being part of the normal human experience into being a medical concern. Therefore, over-diagnosis can only be recognised by looking at how the growing number of people with a mental health diagnosis are benefitting in the long term. If the diagnoses are appropriate, they should lead somewhere positive and allow an easier progression through life.
With that definition in mind, it feels impossible to say that mental health conditions are not over-diagnosed. Consider how the prevalence of autism has grown from affecting one in 2,500 children decades ago to more than one in 100 children today.
More inclusive diagnosis promised to improve long-term mental health and well-being for young people. And yet, mental health diagnoses in adults, particularly young adults, are also steadily growing. This is the very definition of over-diagnosis — more early diagnosis, but no downstream improvement in well-being. Worse, these statistics suggest that the growing population of young people diagnosed as neurodivergent may actually be faring worse in adulthood than any population that has gone before.
A medical label is not inert. It has a power all of its own to make people sick. When you tell a child that they have a neurodevelopmental condition, you risk encouraging that child to focus on what they cannot do. It could create the impression that the difficulties that child is experiencing cannot be overcome. You lower others' expectations for that child. The diagnosis can impact identity formation and become a self-fulfilling prophecy.
Diagnostic labels make social and psychological struggles seem set in stone, which gets in the way of an examination of life that might have a more lasting positive impact on well-being. A thirst for finding mental health diagnoses in milder forms and the growing number of mental health awareness campaigns risk pathologising ordinary differences and encouraging people to worry unduly about the natural highs and lows of mood.
We need to learn how to recognise and support struggling people, and children in particular, without medical labels because the current system is not working. Better lives for children, social change, is how you create healthier, happier adults.
Suzanne O'Sullivan is the author of 'The Age of Diagnosis: Sickness, Health and Why Medicine Has Gone Too Far'
Minesh Patel, Associate director, Mind
It's hard to imagine that if the rates of cancer screening and diagnosis went up through public campaigns encouraging people to be aware of symptoms, to not suffer in silence and to seek support, it would not be a cause for celebration.
But when it comes to mental health, that's where we are. And for many, it's treated as evidence that 'mental health culture has gone too far'. This is despite the fact that the threshold for a diagnosis hasn't changed.
Several senior politicians from across the spectrum have made the argument about over-diagnosis or self-diagnosis, or a variation of it, in the last year. But I think, especially when it comes to the interventions of politicians, it's important to consider the context in which the debate is taking place.
We are talking about a time of tight public finances, a rising welfare bill, and increasing numbers of people unable to work due to mental health problems. We are living in the shadow of a once-in-a-generation pandemic and cost-of-living crisis, both of which we know, from the people we speak to every day, have been substantial drivers of mental health problems.
There are 1.6 million people on mental health waiting lists, with those on low incomes experiencing some of the worst health outcomes. While it has become convenient, or in some cases politically expedient, to deny that the scale of rising mental health problems is real, such denials inevitably lead to policymakers not pursuing a proper appreciation of what might be driving such rises. This increases the burden on both the healthcare system and patients, as the earlier the intervention, the more treatable these issues become.
Our starting point has to be one of understanding the factors behind increasing levels of poor mental health and addressing the delays in people getting support. The solution certainly does not lie in making claims about over-diagnosis, which have little evidence to support them. This is especially the case when many of the people experiencing poor mental health are already facing the sharpest impacts of poverty and will be those hit hardest by proposed welfare cuts.
It's clear we still have a long way to go when it comes to equal treatment of physical and mental health, a point made more real by the proportion of the NHS budget going to mental health falling next year. What's needed now is a conversation that is careful not to stigmatise people's real experiences and does not undermine the expertise of medical professionals. It must instead focus on how we can best create a mentally healthier society – one where fewer people experience poor mental health in the first place.
Joanna Moncrieff, Professor of critical and social psychiatry, UCL, and NHS psychiatrist
With the increasing diagnosis of mental health problems, we are medicalising a variety of human situations that are not medical problems. This has negative consequences for individuals and for society.
Diagnosis is a medical activity. It implies that people have an underlying biological abnormality that is the cause of their symptoms. This is not the case with mental health problems. When someone is diagnosed with depression, anxiety or ADHD, this is simply a description of their problems. It is a label. It is not an explanation. It does not mean there is an underlying biological deficiency.
The widespread belief that depression is due to a chemical imbalance has never been demonstrated, for example, and biological mechanisms have not been established for any other mental health condition. As a result, the process of making a mental health diagnosis is highly subjective. It depends on the beliefs and circumstances of the individual doctor and patient, and it is influenced by general social and economic conditions.
Yet, giving people a mental health diagnosis creates the impression that there is an underlying biological problem. This is harmful because it results in people feeling pessimistic and powerless to change anything. It can lead people to limit themselves. It also results in unnecessary exposure to medical interventions, such as antidepressants. Despite being widely used, there is little evidence that antidepressants are helpful, and plenty of evidence that they can have serious adverse effects.
Moreover, giving people a diagnosis risks overlooking the real problems. It focuses everyone's attention on the symptoms of the condition, rather than the problems that caused them originally. Overwhelmingly, these problems are social, such as poverty, unemployment, relationship problems, loneliness and lack of meaning.
Diagnosing the understandable consequences of these features of our society as medical conditions inhibits social change. It enables politicians to ignore the inequality, insecurity and social fragmentation that have resulted from neoliberal political and economic policies, and which cause so much misery and stress.
In the short term, medicalisation provides financial security for some through the benefits system, but this could be (and in some cases is) done differently, on the basis of need. In the long term, medicalisation perpetuates the system that is causing our mental health crisis in the first place.
Joanna Moncrieff is the author of 'Chemically Imbalanced: The Making and Unmaking of the Serotonin Myth'
Brian Dow, Deputy chief executive, Rethink Mental Illness
There is lots of talk about the over-diagnosis of mental health conditions. But for most people living with mental illness, the reality is often a struggle for a timely diagnosis and access to the right treatment.
Our charity's research found the majority don't receive support quickly enough, with four in five experiencing a deterioration in their mental health while they waited. The consequences are serious: crisis, suicide attempts and lost livelihoods.
Of course, as in any area of medicine, misdiagnoses do occur. Some people in recovery may come to feel that a diagnosis no longer serves them. And yes, we should be doing much more to prevent people from falling out of education or work, rather than simply writing them off.
On the other hand, a diagnosis is often the only way to access life-saving support. And we don't suggest that cancer awareness-raising campaigns are problematic because most people who get checked won't have cancer. Quite the opposite: we encourage people to seek help, knowing that early intervention saves lives. So why discourage the same approach for mental illness, when the effects can be just as devastating?
This is a complex issue that requires nuance, not oversimplification. Right now, there's no compelling evidence of over-diagnosis, but there is ample evidence of a rising tide of mental distress and under-resourced services failing to meet demand. Recent research from the Institute for Fiscal Studies shows that mental health difficulties, particularly among young people, are increasing.
Mental illness has never reached parity with physical health in either investment or priority. Our analysis of NHS data shows someone is eight times more likely to wait over 18 months for mental health treatment than for physical healthcare. The government's target for 92 per cent of patients to start treatment within 18 weeks does not currently include any commitment to tackling waits for mental health services. Against this backdrop, we must be extremely cautious we don't deter people from seeking help. We also need to do more to tackle the drivers of poor mental health, especially given that mental illness often begins young and becomes entrenched without support. That means investing in school-based support, housing, tackling poverty and reducing isolation. This is not soft policy; it's a pragmatic way to reduce pressure on an already overburdened system.
While different conditions require different responses, all mental illness, from mild to severe, is distressing to the individual. What matters is delivering the right support, in the right place, at the right time.
The question isn't whether we're over-diagnosing. It's whether we're doing enough to help.
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