By Nick Haslam, Professor of Psychology, The University of Melbourne, via The ConversationThe Anatomy of Melancholy was written more than 400 years ago, but Robert Burton’s masterpiece is strangely modern. Although it brims with quaint language and Latin quotes, it also resembles a medical textbook: a compendium of the symptoms, causes, prognoses and treatments of human misery.Take Burton’s discussion of “love-melancholy”. Its symptoms include leanness, loss of appetite, hollow eyes, fear, sorrow, disturbed sleep, suspicion, sighing, moaning, peevishness and pallor, “as one who trod with naked foot upon a snake”. It has dietary, climatic and astrological causes. Burton is not optimistic about recovery, but suggests “good counsel and persuasion” may help.Love-melancholy is no longer recognised as an illness, but Burton showed how it could be diagnosed. From Greek roots meaning “to know apart” or distinguish, diagnosis takes place in countless consulting rooms around the globe. In essence, this process of discerning illness from symptoms is no different from any other kind of categorisation, like identifying birds or car models.Diagnosis may be an everyday activity, but it is a contentious one. There has been a staggering rise in the prevalence of many medical conditions and the cultural attention we pay them. Diagnostic labels saturate our language, firehosed by social media. The stigma attached to some diagnoses, such as depression and attention deficit hyperactivity disorder, has waned to the point where many people actively seek and embrace them.But as diagnosis has risen in prominence, it has become a magnet for criticism. New diagnostic manuals are lashed for turning ordinary life problems into pathologies. Mental health professionals argue we should abandon diagnosis altogether, or replace its categories with spectra. Countless video clips on social media channels like TikTok peddle expansive and inaccurate definitions of illness, while others push back against self-diagnosis.Irish (and now UK-based) neurologist Suzanne O’Sullivan enters this battlefield with her timely book, The Age of Diagnosis. O’Sullivan is a seasoned clinician and science writer who has seen firsthand how the diagnostic landscape has changed. We have taken diagnosis too far, she argues, and our cultures, health systems and selves are suffering the consequences.Her perspective is a necessary one, complementing the concerns about overdiagnosis and “concept creep” raised by writers whose backgrounds are primarily in research and theory. As someone who works at the clinical frontline, and whose compassion for her patients is clear, O'Sullivan’s views cannot be written off as out of touch or uncaring.Overdiagnosis and medicalisationO’Sullivan’s case rests on two pivotal concepts: overdiagnosis and medicalisation. We might imagine that overdiagnosis occurs when diagnoses are made in the absence of illness, but O’Sullivan’s definition is more subtle. A condition is overdiagnosed, she writes, when the costs of the diagnosis outweigh its benefits.This definition draws attention away from knotty ontological questions about the boundaries of illness and towards the pragmatic question of whether diagnosis is helpful. “A diagnosis is supposed to lead to something,” O'Sullivan writes, and if it doesn’t lead to something good, it is unwarranted.Ideally, a diagnosis should deliver the benefits of effective treatment while doing no harm. In practice, many diagnoses carry stigma, undermine our sense of self and future, and have self-fulfilling negative (“nocebo”) effects. O’Sullivan argues we systematically underestimate the costs of diagnosis and overestimate its benefits. This is especially so for milder forms of illness, where the benefits of treatment are often minimal.Medicalisation is the tendency for concepts of illness to expand to encompass a widening range of human experience. New conditions can be invented and old ones stretched to include milder phenomena. Ordinary variations in human biology can be defined as disease risks, as in “predictive diagnosis”, when the likelihood of developing a condition is calculated based on genetic tests or other health information.Medicalisation leads us to see the world through the lens of pathology. By expanding concepts of illness into the zone of ordinary unhappiness, O'Sullivan argues, it fosters overdiagnosis.Attributing more to sicknessO’Sullivan believes overdiagnosis and medicalisation are rife. Rates of some diagnoses are rising, not due to declining population health or enhanced detection, she suggests. Instead, “borderline medical problems are becoming ironclad diagnoses”. “We are not getting sicker,” she writes, “we are attributing more to sickness.”This trend has several adverse consequences. Overdiagnosis leads to overtreatment. Because diagnoses are not inert labels, it can actively create illness and distress. It can waste resources and divert them from areas of greater need.Chapters of the book explore these themes in a range of health conditions, many psychiatric or neurological. They offer an informative combination of clinical case study, clearly articulated science, and sober reflection on social implications.A chapter on autism chronicles the steady expansion of this condition. Originally a severely disabling and vanishingly rare condition of childhood that disproportionately affected boys, it has become one that encompasses people with relatively benign challenges, she writes. Increasingly, it is diagnosed in adults and the sex ratio is gradually becoming more balanced.For O’Sullivan, these developments reflect “diagnostic creep” and questionable theorising. The autism phenotype has become overstretched, she argues: concepts such as “masking” allow people with relatively mild visible social impairments to be included. Many people find autism diagnoses validating, she argues, but evidence they produce benefits for everyday functioning is scarce. She also warns autistic identities may be stigmatised and self-limiting.Meanwhile, heterogeneous samples and shifting diagnostic sands make it well-nigh impossible for researchers to develop reliable, cumulative knowledge about autism. It has become a moving target: a paradigm case of philosopher Ian Hacking’s “looping effects”, by which our classifications influence the people they classify – and are then influenced by them.Critical of neurodiversitySimilar concerns are raised about attention deficit hyperactivity disorder (ADHD). Like autism, the diagnosis has increased rapidly and received many more adult and female cases. O’Sullivan notes the unavoidable subjective elements involved. All 18 “symptoms” must be judged to occur “often” to be considered present, a judgement known to vary between people. These symptoms must be appraised as “negatively impacting” social, academic or occupational activities, another intrinsically vague benchmark.O'Sullivan is critical of the “neurodiversity” view of ADHD, which holds that the condition is a form of difference to be celebrated rather than a disorder to be fixed. She denies that its essence is neurological and challenges the “biologising” focus on brain processes. That focus oversimplifies ADHD, overlooking its social and environmental determinants. “I am a psychologiser,” she announces, sceptical of biological reductionism.The recent trend for ADHD to be adopted as an identity also comes in for criticism. O’Sullivan sees this identity as more constraining than liberating. Viewing ADHD as an enduring and inbuilt aspect of one’s brain promotes passivity, and the bogus binary between the neurodivergent and the neurotypical creates an unhelpful “us versus them”, she writes.O'Sullivan acknowledges that many people find self-acceptance in the diagnosis. However, its additional benefits are unclear, she suggests, especially among relatively mild cases. For example, stimulant medication may not compensate for the adverse impacts of diagnostic labelling for children with less severe ADHD. Similarly, study accommodations such as extra time on tests have little effect on performance. In the absence of tangible benefits and the presence of potential costs, she argues, ADHD is likely to be overdiagnosed.Overscreening cancerAlthough many of the book’s examples scrutinise mental health, The Age of Diagnosis roams wider. O’Sullivan gives equal weight to Huntington’s disease, Lyme disease, long COVID and rare genetic conditions, among others. In these conditions, tensions often arise between advocacy groups and medical scientists. The former typically agitate for broader and sometimes questionable diagnoses. O’Sullivan makes no secret of where she stands:Scientific answers aren’t at the convenience of the majority opinion. Understanding patient experience is fundamental in setting research priorities, but scientific process must still be systematic, methodical, rigorous and open to any answer.In a powerful chapter on genetic screening for cancer, Sullivan finds it often fails to deliver health benefits but succeeds in pathologising normal biological variations. All screening tests have false positives, but these can be significantly more common than true positives. False positives are not cost-free and the benefits of accurate early detection are not straightforward.Positive tests can have damaging psychological and sometimes physical consequences, she writes. These include dread-filled time waiting for disease to manifest and unnecessary interventions. Some screening tests massively overestimate the likelihood that positive tests will develop into illness requiring treatment.Even if screening reduces progression to a particular fatal disease, it may not reduce deaths by all causes combined. O'Sullivan cites one meta-analysis showing that with the exception of large bowel cancer, cancer screening did not extend the lifespan at all. It is instructive that people who are properly apprised of the potential risks and benefits of screening often forego it, even when the benefits are relatively unambiguous.Fixing the diagnosis problemWhat to do? O’Sullivan is not one to wring hands. She offers a range of remedies, some directed at medical practice and some to the culture at large.From the standpoint of medicine, O’Sullivan’s key recommendation is to take overdiagnosis much more seriously. Greater scrutiny is required whenever definitions of disorders are loosened or new screening tests are developed. Deeper scepticism about the aggregate benefit for patients’ quality of life is also needed. More attention must be paid to the potential downsides of diagnosis.A more nuanced understanding of diagnosis itself is required. Often the problem is not diagnosis itself, but doing it too mechanically and taking it too literally. Diagnosis is a clinical art, not something decided by a superficial checklist or lab test.O’Sullivan makes an evidence-based case for the importance of clinical judgement, informed by intimate and holistic awareness of the patient’s life circumstances. That kind of awareness is the best done by generalists, endangered as they are in our age of specialists.Humanistic care is essential, but it is not enough. There is an urgent need to arrest the proliferation of diagnoses. O’Sullivan observes that patients increasingly present with multiple diagnostic labels, and discusses the poignant case of a young woman with nine.The problems this trend poses should be obvious. Multiple diagnoses draw in multiple specialists, call for different treatments, make the coordination of care a major challenge, and become all-absorbing for the patient. The stickiness of diagnostic labels means that conditions are added but rarely subtracted.Frequently the multiple diagnoses are not meaningfully distinct “co-morbid” ailments, but different expressions of a single underlying emotional disturbance, O'Sullivan suggests. Splintering this disturbance into a motley assortment of diagnoses fragments treatment. Like the fabled blind men who palpated different parts of an elephant, identifying it as a snake, spear, tree trunk, rope and wall, it also gets the ontology of the illness wrong.Changing the culture of diagnosisResponsibility for solving this problem should not fall on health professionals alone, however. It requires cultural change as well. Once upon a time we could blame the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) for medicalising experience and shrinking normality. But now inflationary trends in diagnosis are driven more by social media and well-meaning efforts to boost awareness.The DSM may have helped to create a diagnostic culture, but it is laypeople who are now stretching its concepts and bandying about illness labels to diagnose themselves and others. This change is often seen as a welcome democratisation of mental health, a belated recognition of the value of “lived experience”, and a form of resistance to the biomedical model. However, its effect has been to pathologise everyday life as much as to normalise mental ill health.The pitfalls of these expansive concepts are now well documented in the research literature. People who apply diagnostic labels to their depressed mood tend to deal with it ineffectively. Making anxiety central to one’s identity is linked to coping poorly with it. Those who define adversities as traumas are more likely to respond in post-traumatic ways to unpleasant experiences.Holding expansive concepts of mental illness leads people to self-diagnose at relatively low levels of distress. Applying diagnostic labels to mild or marginal cases of suffering leads people to think recovery is less likely and troubles less controllable. Findings such as these indicate that whatever benefits baggy diagnostic concepts may have, they also have a significant downside.A growing ‘dediagnosis’ movementThe realisation that rising awareness of and attention to mental illness may be backfiring is beginning to dawn. There is little evidence it is improving our mental health – which continues to decline globally as awareness grows, especially among the young. However, there is reason to worry it may be doing the opposite.A similar story might be told about other forms of illness. It is not hard to believe elevated concerns about risk and the medicalisation of normal losses of physical function can drive a joyless pursuit of perfect health and happiness.O’Sullivan is correct in diagnosing our “age of diagnosis” and she makes a strong case for moving beyond it. It is hard to say what a post-diagnostic age might look like and how the pendulum might be wrestled back. It will surely require significant reform on the part of health systems and a serious reckoning with the rise of screening tools.In this connection, it is gratifying to see an emerging movement for “dediagnosis” within medicine. It will have to be accompanied by a transformation in how the public thinks about diagnosis. O’Sullivan’s masterful book could help bring such an alliance into being.The Age of Diagnosis shows us how we got into our pathological predicament – and indicates how we might get out.
