In the field of mental health law,we entrust decisions with consequences of the utmost gravity – decisions about compulsory medical treatment and the loss of liberty – to doctors and approved social workers. Yet, how do these non-lawyers make decisions where the legitimacy of those decisions derives from law? This book examines the practical, ethical and legal terrain of duo-disciplinary decision-making: given identical cases, what dilemmas do psychiatrists and approved social workers encounter, do they reach the same or similar decisions and, most critically, how are those decisions justified? At a time of ferment in mental health law this book, through its narrative format, aids a better understanding of the dilemmas posed.