The preparation of a second edition of this book has given us the opportunity to cover the major developments in mental health legislation since the publication of the previous edition. These have included the new Mental Health Act 2007, the Mental Capacity Act 2005 together with its two Codes (one general and one covering the Deprivation of Liberty Safeguards), the revised Mental Health Act Code of Practice published in 2008 and changes in legislation related to research involving the mentally disordered. Once again, we have sought to strike a balance between the need to provide the reader with a relatively short and portable handbook containing practical advice and the desire to be over-inclusive with detailed considerations of the ramifications of legal argument. While the usual cautionary legal principle is that the reader should always refer to the latest primary legislation, this is rarely realistic in day-to-day practice. However, it is hoped that the new edition of this mental health law handbook will continue to live up to its name and provide helpful practical medico-legal advice. We wish to thank all those who reviewed the first edition and the draft second edition and we are grateful for the feedback we received. We are very sorry to relate that Dr Paul Laking, the author of the excellent chapter on child mental health law in the first edition, has died. We valued his contribution greatly and extend our sympathies to his family