This book is an introduction to the UK's complex and rapidly developing area of law in relation to the vulnerable, namely children and those adults who lack capacity. The book provides practical guidance and assistance to the approach taken by the UK's courts on all of the varying issues raised in relation to medical treatment and the law, the thread of which, throughout, is the question of consent. Many who suffer from mental illness are well able to make decisions about their medical treatment, and it is important not to make unjustified assumptions to the contrary. The book will be of assistance not only to the legal profession and judiciary, but also to those working within the field of medicine or other areas concerned with the welfare and protection of the vulnerable, whether adults or children. The book also includes an analysis of the Supreme Court's judgments in specific UK cases which encompass the issues concerning assisted suicide, mercy killing, and voluntary euthanasia. Subject: Family Law, Children's Law, Medical Law, Mental Health Law]