Sam's guest in this week's Book Club podcast is Horatio Clare - whose superb latest book is about going mad. Heavy Light: A Journey Through Madness, Mania and Healing, tells the story of Horatio's recent breakdown and forcible hospitalisation - what he experienced, how he recovered, how it pushed him to investigate the unquestioned assumptions about 'chemical imbalances' causing mental illness, and the questionable and effectively random ways in which drugs are prescribed.