The history of medicine abounds with oddball characters and bizarre events. Yet few figures are quite as eccentric as the French neurologist Jean-Martin Charcot and few episodes reach the levels of absurdity displayed in his demonstrations of “hysterical” women being hypnotised in Paris in the late 19th century. Charcot had begun so promisingly. Early in his career he made groundbreaking discoveries in multiple sclerosis and Parkinson’s disease, thereby earning himself the epithet “father of neurology”. But he became fixated on “hysteria”, a catch-all diagnosis that Victorian doctors applied to unconventional behaviour that defied medical explanation. For more than a decade Charcot hypnotised scores of patients, mostly women, at the Salpêtrière asylum in his quest to show their condition had a biological cause rooted in the brain. According to his twisted logic, if patients reproduced their strange antics and seizures under hypnosis this proved their illness was real not feigned and was therefore a physical not a mental disorder. Crowds of eminent doctors and scientists, the vast majority male, packed the hospital to watch Charcot induce his patients to adopt ridiculous poses and act out ludicrous scenes. His star patient, Blanche Wittmann, known as “queen of the hysterics”, had been sexually abused as a teenager. Under hypnosis she was persuaded to cower in fear of an imaginary snake, lead her troops into battle as a pretend general and remove her clothes. It is a wonder Charcot’s spectators did not march him to the cells after these performances rather than his unfortunate victims. Yet paradoxically all this time he was surrounded by an epidemic of manic behaviour that filled psychiatric institutions and was truly caused by brain disease – neurosyphilis. While he, the founder of neurology, was obsessed with proving that mental illness was caused by lesions in the brain, patients with neurosyphilis were left to the forerunners of modern psychiatry. Portrait of Jean-Martin Charcot, 1890. Photograph: Bettmann Archive In this absorbing and scholarly book, Allan Ropper and Brian Burrell home in on Charcot’s strange shows as the seminal moment when psychiatry and neurology split and began their journeys along separate but intertwining paths towards a partial convergence today. A twin biography of psychiatry and neurology, their study charts this uneasy relationship from marriage to divorce to reconciliation even as fundamental questions about the nature of mental illness remain. In a story that zigzags through time and criss-crosses the globe, they explore the discovery of hypnosis, the birth of psychoanalysis, the identification of Tourette syndrome, the revolution in psychiatric drugs and up-to-the-minute research on the study of the brain. Yet it is neurosyphilis, a condition once “as traumatising and destructive as Aids” but now extremely rare, that dominates. Having appeared in the west in the 1500s, syphilis had reached epidemic proportions by the 19th century. With no effective treatment or cure, it afflicted an estimated one in 10 people. Fear of catching the disease dominated 19th-century society and suffused its art and literature. The streets “teemed with syphilitics”, according to Ropper and Burrell, and the “landscape of sexual pleasure was mined with appalling risks”. Some men never married to avoid passing syphilis to their wives; others conveyed it to their brides on their wedding nights. Women passed syphilis to their babies; wet-nurses spread syphilis from one baby to another. An American heiress, Mabel Dodge, caught syphilis when she began an affair with her father’s doctor, caught it again from her third and fourth husbands, and underwent an abortion for fear of passing congenital syphilis to her unborn child. Although the symptoms of untreated syphilis in its first and second stages usually disappear after a few weeks, the infection can then remain dormant. In about one third of cases it reappears years or decades later in a devastating attack on bones and soft tissue, often targeting the heart and brain. In the brain it causes symptoms including delusions, hallucinations and dementia. Thousands of people suffering these tertiary effects of syphilis on the brain were diagnosed with “general paralysis of the insane” and packed into asylums. Ropper and Burrell estimate that as many as one in five patients in Victorian psychiatric hospitals had neurosyphilis; their numbers included writers such as Guy de Maupassant, who died in an asylum aged 42, and Gustave Flaubert, who suffered its symptoms for four decades. Those not made mentally ill by syphilis were often driven so by mercury, the standard treatment for the disease. Ropper and Burrell estimate that one in five patients in Victorian psychiatric hospitals had neurosyphilis Eventually syphilis was vanquished by penicillin. Yet it left an important legacy: the notion that mental illness can be generated by a biological cause in the brain. Evidence that those dying in vast numbers in asylums showed common changes in their brains was first noted in post mortems in the 1820s but the link with syphilis was only made 30 years later. It was this realisation that kickstarted the discipline of neurology and set its followers on their separate but colliding path with psychiatry. But the tug of war over whether mental illness is located in the brain or mind continues. Freud’s flawed theory of psychoanalysis – the awkward lovechild of neurology and psychiatry – created a long diversion. But eventually, Ropper and Burrell argue, neurology and psychiatry “have settled into a kind of algorithmic minuet, dispensing diagnoses and drugs while each one dances around the central question of the nature of mental illness”. Conditions with common patterns, such as schizophrenia, depression and Tourette syndrome, may one day reveal biological causes but evidence is so far inconclusive. One in five outpatients visiting neurology clinics show symptoms as baffling as the “hysterics” who packed Charcot’s clinic. The questions Burrell and Ropper raise are as intriguing as their answers. How do we distinguish between brain and mind? And which mind do we mean: our accumulation of experiences or the way we process them? It’s a complex and convoluted story but one made highly readable and hugely entertaining by this authoritative book. • Wendy Moore’s The Mesmerist: The Society Doctor Who Held Victorian London Spellbound is published by W&N. How the Brain Lost Its Mind is published by Atlantic (RRP £17.99). To order a copy go to Free UK p&p over £15.