This article is taken from the June 2025 issue of The Critic. To get the full magazine why not subscribe? Right now we’re offering five issues for just £25.
Diagnosis is key to the doctor-patient relationship. Without the ability to name our ailments, we’d be in physical and mental turmoil. Treatments would be inaccessible or unsafe. Those of us with conditions for which a cure is unavailable know that a label will help. We will understand ourselves better; it will be easier for others to understand us. Investment in aids to diagnosis — scanners, screening programmes, genetic research — is money well spent. Only the fearful, the infantile, would disagree.
It’s unfortunate that only the first of these statements is true. In The Age of Diagnosis Suzanne O’Sullivan dismantles, with meticulous care, why our confidence in classification as a straightforwardly Good Thing is misplaced. Having spent two decades as a consultant neurologist, she acknowledges the value of new tests and technology. These advances have made O’Sullivan’s work easier. But results are not simple to interpret. There are variables, false positives, irrelevancies. In her view diagnosis should remain centred on “the patient’s story”. This may be why the most telling passages in The Age of Diagnosis occur when she steps back, letting her patients speak.
Take Stephanie, who has a family, a job and a long history of seizures. It was only when she reached middle age, that scientific advances meant her epilepsy could be linked to a rare gene variant. As her doctor, O’Sullivan was enthusiastic about this step forward. Stephanie saw things differently.
Until my forties, I didn’t know I had a genetic condition, so I just got on with things … When I didn’t know I had the abnormal gene I could still hope it would all go away.
O’Sullivan’s earlier book, the prize-winning All In Your Head, explored psychogenic disorders — conditions in which mental stressors cause physical symptoms that match other illnesses. So, she is well-placed to explore the effect that being diagnosed has on body and mind. The Age of Diagnosis makes it clear that whilst diagnosis can seem like an endpoint, it is only a beginning.
An early chapter deals with the inherited neurodegenerative condition, Huntington’s Disease. Before predictive testing was available, the majority of people in affected families declared their willingness to be tested. Then the gene was identified. For the last 40 years, people have been able to find out whether or not they will develop the disease. Worldwide, around 90 per cent of those who go to clinics and are offered the test ultimately choose not to take it. A geneticist at one clinic told O’Sullivan, “Often all I need to do is give people permission not to test … It gives people peace of mind to learn they don’t have to.”
There is no cure for Huntington’s Disease. Trepidation is natural. But what about predictive screening for women who may carry the BRCA1 and BRCA2 genes, which are linked to various cancers? One might imagine this to be less demoralising.
But when a condition is seen as treatable, the protective rituals which apply to other types of screening are cut back. O’Sullivan cites the example of 25-year-old Roisin, whose maternal family history made it likely she inherited these genes. After just one counselling session, she gave a blood sample. A few weeks later, Roisin was at work
when her phone rang with a number she didn’t recognise. That was how the counsellor told her that she had a high-risk BRCA1 variant that gave her an 87 per cent chance of developing breast cancer and 60 per cent chance of developing ovarian cancer.
The foremost option for women in Roisin’s situation is risk-reducing surgery — the removal of healthy breasts, ovaries and fallopian tubes. In theory, pre-diagnostic and diagnostic processes give us agency over our bodies, our lives. In practice, the drive to diagnose sets off a chain of events that we find it difficult to control.
In its last chapter, The Age of Diagnosis explores the apparently benign world of non-invasive prenatal testing (NIPT). This is a blood test used to assess probabilities, rather than an overtly diagnostic procedure. The per centages it generates are not 100 per cent robust, and the figures are often misinterpreted, making risks look greater. Yet significant numbers of those who undergo NIPT will be urged to follow a particular path.
We are told about Ayla, a mother-to-be, whose 12-week scan showed a high risk of Down’s Syndrome. Ayla had already made her choice — to have her baby — but was still pressured into having NIPT. Subsequent hospital visits involved conversations about not having to go through with the pregnancy. O’Sullivan states, “Ayla was offered a termination seven times during her pregnancy with the last offer a week before her baby was born.”
O’Sullivan is clear that prenatal screening offers benefits, but we are left to wonder if tests are a way to reintroduce eugenics through the back door. There are fewer children with Down’s Syndrome in the world now. It seems ironic that even as we claim to embrace diversity, our increasingly medicalised culture risks stigmatising — and doing away with — difference.
For serious conditions, the case for diagnosis is stronger. Yet, in one of the paradoxes highlighted by The Age of Diagnosis, it is those with the less severe forms of any condition who claim their new labels most eagerly. With autism and ADHD, the rationale for picking up mild cases rests on the benefits that intervention has for children. This has not stopped fairly successful adults, people with partners and careers, from lining up to get diagnosed. O’Sullivan, who has interviewed many such individuals, comments:
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.
The Age of Diagnosis explores new dilemmas, but the underlying problems have been around for a long time. The term diagnosis first appeared in English in 1681, in a work called A Table of Hard Words. Those with a love of Romantic literature will be inclined to view O’Sullivan’s work as a reworking of the age-old debate between Innocence and Experience.
It is part of the human condition that we grow in knowledge. But at what cost? Here is the poet Thomas Gray in 1742, looking at children from a distance:
Yet ah! why should they know their fate?
Since sorrow never comes too late,
And happiness too swiftly flies.
Thought would destroy their paradise.
Medicine may have demolished Eden, but the pleasure of thinking remains. O’Sullivan looks on diagnosis as an art and a science, but believes that art should take precedence. Artistically, The Art of Diagnosis has a lot going for it. There is a reliable narrator, a rich cast of characters. With its intriguing narratives and ever-shifting perspectives, readers will find it a most thought-provoking book.
