Richard Smith , 2025-04-16 14:11:00
Darcie is a woman in her early 20s with migraine, hypermobile Ehlers-Danlos syndrome, anorexia, irritable bowel syndrome, postural orthostatic tachycardia syndrome, autism, attention deficit/hyperactivity disorder (ADHD), depression, and anxiety. She was referred to the neurologist Suzanne O’Sullivan because she developed seizures. O’Sullivan, who specialises in psychosomatic conditions, ran elaborate tests, and, as she expected, found no brain disease in Darcie. She emphasises, however, that Darcie is not faking her seizures and that they are “as disruptive to life as a brain disease like epilepsy.”
Seeing many patients like Darcie disabled by multiple diagnoses has been one stimulus that has led O’Sullivan to write her new and important book, The Age of Diagnosis: Sickness, Health and Why Medicine Has Gone Too Far.1 Why are people, particularly young people, accumulating so many diagnoses? Another stimulus has been the huge increases in numbers of people having a disability, receiving a widening range of diagnoses, or experiencing mental health problems.
People in Britain who receive a disability benefit rose from 3.9 million in May 2002 to 6.9 million in February 2024.2 More than half are receiving the benefit because of a mental health disorder. Around two million people in Britain, almost 3% of the population, have long covid, a condition first named on Twitter (X) on 20 May 2020.3 O’Sullivan writes that, in her view, most cases are psychosomatic, and she’s received much criticism as a result.
A 2023 study found a 20-fold increase in ADHD diagnoses and a 50-fold increase in ADHD prescriptions in men aged 18-29 from 2000 to 2018.4 A 2021 study showed an eightfold increase in new diagnoses of autism from 1998 to 2018, and 1.2 million people in England are waiting to be assessed for the condition.5
Antidepressant prescriptions almost doubled in England from 2011 to 2023, rising from 47.3 million to 85.6 million.6 These patterns are not unique to the UK. In the US, rates of depression and anxiety in children increased from 5.4% in 2003 to 8.4% in 2012.7 O’Sullivan writes, “The charity Lyme Disease Association of Australia estimates that as many as half a million people have been diagnosed with Lyme disease acquired in Australia, despite scientists claiming this is impossible.”
People want diagnoses
Rising diagnoses are not restricted to mental health problems. The appearance of diagnoses of prediabetes and prehypertension increased by millions the numbers of people with a diagnosis in the UK alone. Screening tests—for example, for prostate and breast cancer—give many people a diagnosis that may lead to effective treatment but may also prove eventually to be a false positive or lead to drastic treatment that may not have been necessary. As O’Sullivan points out, patients who have surgery for cancers that wouldn’t have killed them will count as successes, increasing the appetite for screening. The risk of unnecessary surgery increases with screening for genes associated with cancer.
Do these increases in diagnoses reflect increases in disease, better awareness, diagnostic drift, or something deeper? There’s little convincing evidence of a true rise in disease and certainly not enough to explain the explosion in many diagnoses. O’Sullivan shows that with most diagnoses the increases are among people with mild conditions. There are, for example, children severely disabled by autism, but the dramatic rise is in people with mild disability who until recently would not have had autism diagnosed. Editions of the Diagnostic and Statistical Manual of Mental Disorders—the psychiatrists’ Bible—have broadened the definitions of conditions such as autism, ADHD, and pathological grief disorder. O’Sullivan believes that the big increase, however, is in enthusiasm for diagnoses among health professionals and among people who self-diagnose. “Doctors,” she writes, “are a little seduced by [their] roles in people’s lives as rescuer and comforter.” If people want diagnoses they shall have them.
And people do want diagnoses. O’Sullivan spoke to a great many people in preparing her book and found that almost everybody with a mild or what might be called an “uncertain” or “dubious” diagnosis was pleased to have been given it.
“People,” she writes, “are struggling to live with uncertainty. We want answers. We want our failures explained. We expect too much of ourselves and too much of our children. An expectation of constant good health, success and a smooth transition through life is met by disappointment when it doesn’t work out that way. Medical explanations have become the sticking plaster we use to help us manage that disappointment.” Unfortunately, O’Sullivan observes, there’s little evidence of the diagnoses leading to an improvement in people’s lives, relationships, or work.
Diagnoses also bring risks. There are the obvious risks around employment and insurance, but they can also bring symptoms. O’Sullivan writes, “Diagnostic labels have the power to create illness in the absence of disease because thoughts, ideas and emotions are enacted through the body.” The symptoms come after the diagnosis or are worsened by it. The flutterings and discomforts we all feel in our bodies can develop to fit the diagnosis.
Central to identity
O’Sullivan begins her book with a chapter on Huntington’s disease: a condition where, unusually, a positive test for the gene definitively means that you have or will develop the disease and a negative test means that you don’t have it and never will. Before the genetic test was developed, people interested in the disease assumed that everybody at risk would have the test as soon as it was available—but most people don’t.
Indeed, in the NHS in England you need three consultations with a genetic counsellor before having the test for Huntington’s disease, to make sure that you fully understand the consequences of a diagnosis. This contrasts with other diagnoses being handed out far too easily and assumptions that if, for example, we had a test for dementia (which will never have the same predictive value as a test for Huntington’s disease), everybody at risk would want the test.
The book tells the story of two daughters of a woman with Huntington’s disease. They had watched the condition develop in their mother and knew the symptoms. Both daughters began to develop symptoms—knocking into things, forgetting names, and the like—and both assumed that they had the condition. But when tested, one sister did, and one didn’t.
A diagnosis can become central to somebody’s identity. O’Sullivan includes a quote from a patient with mild autism: “Without autism, I wouldn’t know I’m not lazy. I know now that I can’t physically make myself do things because I have the wrong dopamine. Without autism, I would never have learned that I have pathological demand avoidance. I would never have learned that there’s a reason that I have all the things that I have been so insecure about my entire life.”
The patient thinks of herself as an “autistic person” because being autistic is integral to who they are. Having long covid, Lyme disease, or ADHD can define who and what you are, and it can make you part of a community. It may even give you a cause—for example, fighting for more research into the condition or participating in developing guidelines on the disease. But, warns O’Sullivan, “When a medical problem is part of a person’s identity, it becomes inescapable.”
People with one diagnosis may join a group with that diagnosis and then be exposed to information not only about that condition but about others that may cause similar symptoms. This is probably how Darcie managed to accumulate so many diagnoses.
Diagnoses can be disabling for individuals, and they can also harm others. The proliferation of people with mild disease can detract from the attention and resources available for people with more serious forms of the disease. People may then become unable to work and need to live off benefits. The UK government has been unnerved by a rise in disability benefits from around £1.1bn in 1985-86 to £39.1bn in 2023-24. The projection is that total health and disability benefits will continue to rise, reaching £100.7bn by 2029-30.
The government has responded by cutting benefits, but cuts are a blunt instrument for distinguishing between people with profound needs and those who might not only be able to work but would benefit from doing so.8 O’Sullivan, whose compassion comes through clearly in her writing, makes clear in her BMJ podcast that she doesn’t support the benefit cuts—but ironically it’s the huge rise in diagnoses that makes her book not just medically but also politically important.
External stressors
O’Sullivan doesn’t have a solution for the rising diagnoses, but she makes clear that the rise is excessive and is bringing more problems than benefits. She calls on doctors to be more careful, emphasising that diagnoses can rarely be made on test results alone. They require careful consideration of the clinical history and the full circumstances that have led people to come to a doctor.
O’Sullivan describes herself as a “psychologiser”: “I hope that helping people to understand that something in their social environment has made them sick will give them control over how to deal with external stressors in the future. I fear that a view that talks too much about internal biological processes makes people passive victims of their medical disorder, which takes away their control.”
As I read O’Sullivan’s book I began to reflect on what might be called the medicalisation of our whole society. Alongside the rising diagnoses are data showing that almost half of all public expenditure is now on the NHS, rising sharply from 25% just two to three decades ago. The NHS is now the biggest employer in the country. From 1949 to 2018 the population of England and Wales grew by 30%, but the number of hospital consultants in England increased 13-fold. Yet there are 7.5 million cases on waiting lists, and public satisfaction with the NHS has fallen to its lowest point, with only 21% saying that they are satisfied.
In Ivan Illich’s 1976 book Limits to Medicine,9 a dense but beautiful text that I return to regularly, he writes of three kinds of iatrogenesis: clinical, social, and cultural. In the section on clinical iatrogenesis he writes of ineffective medicine and injury from medicine—topics that are familiar now but were less often discussed in the 1970s, when modern medicine seemed to be sweeping all before it. Features of social iatrogenesis listed by Illich include the huge growth and increasing cost of healthcare and the rise in the size, range, and power of drug companies.
But cultural iatrogenesis is perhaps the most important and ultimately pernicious. Illich starts from the irrefutable premise that suffering, pain, sickness, impairment, failure, disappointment, decline, and death are unavoidable parts of life. Traditional cultures, often with religion to the fore, provided means of dealing with and finding meaning in such phenomena. Modern medicine, argues Illich, has swept those traditional means away with a false promise of being able to manage those phenomena by largely technical means. We’re left stranded, certainly when it comes to providing meaning as opposed to drugs or surgery. “Cultural iatrogenesis,” he wrote, “sets in when the medical enterprise saps the will of people to suffer their reality.”
Illich, who died in 2002, did see disease steadily spreading as medical power mounted, but he didn’t foresee people seeking diagnoses to provide a label and meaning to the problems, failures, or disappointments in their lives. But it’s not surprising: where else are people to look when, as Illich argued, “health care has become a monolithic world religion”?
My final thought when reading O’Sullivan’s magnificent book was to remember the prediction of Uwe Reinhardt, the witty professor of health economics at Princeton, that eventually “everybody will be either working for a hospital or in one.”