It is lucky for us that Ludwig van Beethoven was more well-known than most during his lifetime as much more information about his life (and death) survives as a consequence. François Martin Mai, Professor of Psychiatry at Ottawa Hospital, has meticulously analysed all the existing material and provides a revealing insight into the life and death of Beethoven and how his health and state of mind affected his music.

Beethoven was a prolific letter-writer – over 1500 of his letters are still in existence, from which Professor Mai has extracted every reference to Beethoven's numerous medical conditions and considers them in the minutest detail, splitting them into the various affected systems. In addition, he supplies absorbing tables denoting each medical problem and which letter it is from, and lists them all chronologically. Intriguingly, there are more references to Beethoven's mental health in his letters than any other ailments, even deafness. In 1802 he considered suicide but wrote that ‘It seemed impossible to leave this world before I had produced all the works I felt the urge to compose’.

Beethoven's ‘conversation books’ (which are the actual written ‘conversations’ used to communicate with him towards the end of his life after profound deafness had descended) are also consulted. These are truly unique and, as Mai points out, they are ‘of special interest as some of the very few verbatim reports of doctor-to-patient communication we have from the pre-electronic era’. The extracts from these books are simply riveting. The author even provides his own new translation of the autopsy report (originally in Latin) as well as some wonderful plates and comprehensive appendices. The final compelling chapter discusses the links between mental state, physical illness and creativity, drawing on Mai's vast experience as both psychiatrist and musician.

Diagnosing Genius is not only exhaustively researched and authoritatively written, it also provides an extraordinary snapshot of the world of medicine during Beethoven's life, composed in layman's terms that will appeal to an enormously wide audience.