The Age of Diagnosis

'Slices through the confusion and the contradictions with grace and compassion. I cannot say good enough things about it.' - CHRIS VAN TULLEKEN

'Be prepared for compassionate and bracingly independent thinking' - THE TIMES, best books of 2025

From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good?

The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell.

An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and reframes how we think about illness and health.

About the Author

Dr Suzanne O'Sullivan has been a consultant in neurology since 2004, first working at The Royal London Hospital and now as a consultant in clinical neurophysiology and neurology at The National Hospital for Neurology and Neurosurgery, and for a specialist unit based at the Epilepsy Society. She specialises in the investigation of complex epilepsy and also has an active interest in psychogenic disorders. Suzanne's first book It's All in Your Head, won both the Wellcome Book Prize and the Royal Society of Biology Book Prize and The Sleeping Beauties was shortlisted for the Royal Society Science Book Prize. She is from Dublin, Ireland.