Joel Paris, a professor of psychiatry with extensive clinical experience, brings his familiar critical stance to the issue of overdiagnosis. The book is written in an engaging, jargon-free style that is accessible to both professionals and the interested public. It begins by considering possible overdiagnosis drivers from the perspective of patient, clinician and researcher. After a discussion of how these happen in each of the major mental disorders, the tenuous relationship between the idea of ‘normality’ and ‘psychopathology requiring a diagnosis’ is discussed. Throughout, Paris does not shy away from the issues surrounding psychiatric diagnoses. The book's central thesis draws upon the danger of medicalisation: a term first used by the Russian social critic Ivan Illich in 1975 to describe the tendency to conceptualise normal variants in everyday life as medical conditions requiring treatment. Paris warns of the current lack of any objective measure to distinguish normal from abnormal, and describes the pressures on clinicians to diagnose ‘normal’ as psychopathology. Factors influencing this, such as the pharmaceutical industry, the lack of construct validity in some epidemiological studies, and problems with the subjectivity of psychiatric diagnoses are explained in frank and simple terms.

As such, the book is essentially a cautionary tale about where psychiatry might have gone wrong. However, unlike other books that follow along these lines, it is never implied that these mistakes will continue to be made; nor does it become critical of the profession at any point. Rather, by addressing the issue from different perspectives, the reader is encouraged to play their own part in addressing the problem. Paris's stance on ‘humility in the face of ignorance’ is illustrated, for example, in addressing the issue of ‘normality’. He systematically discusses the problems with currently accepted definitions of the term, but not once does he attempt to suggest the ‘right’ way of approaching it. This is not a book of answers, so perhaps it will not satisfy every reader, but by avoiding the natural tendency to concentrate on what is known, Paris is an honest guide.

Overdiagnosis has become topical. Paris touches on stories in the media about the apparent rising prevalence of mental disorders, and on the ready availability of medical information on the internet driving the ‘worried well’ to seek psychiatric help. He dedicates the book to his fellow researchers for teaching him the importance of caution in clinical practice. For his readers, both patients and psychiatrists, I believe this book could do the same.