The first edition of this book (2002) took a practical, problem-oriented approach to applying evidence to determine dementia practice. The field has moved on since then, with many initial breakthroughs in both diagnosis and treatment not being supported by further evidence. This has not prevented well-meaning enthusiasts evangelizing certain approaches. The time has come for a new edition of this book that critically analyses what works at a practical level. The problem-based approach of the last edition will continue. Coverage of genetics, imaging and treatment will be increased. Now irrelevant material will be excised (and possibly archived on a website to be hosted by Nawab Qizilbash, the lead Editor).