Book excerpt: Given the unacceptably high rates of suffering, disability and premature death experienced by people with treatment-resistant depression and the surprisingly low rates of problems arising from the use of ketamine to treat the disorder, this is a therapy that all patients and their doctors should be discussing. This book summarises the research that has been carried out into ketamine for the treatment of depression over the past 15 years and, most importantly, describes different ways of using ketamine that are both practical and cost–effective. Currently most ketamine therapy is given intravenously in specialised clinics at considerable expense, but the author has successfully treated patients with low-dose sublingual ketamine and his patients have been able to safely take this at home. Profits from the sales of this book will assist further research into the use of ketamine for the treatment of depression.