This book highlights the fact that leaders do indeed affect the performance of organizations or the well-being of society for better or worse—to cast either a shadow or light by the exercise of their leadership. Modern psychology with its theories of human behavior, which does not acknowledge the existence of the spiritual realm, cannot explain the carnage and evil often associated with the dark side of leadership. This book focuses on the dark side of leadership in a multidimensional manner and provides a psychospiritual approach toward understanding personality disorders and leader derailment. It highlights an area that has not been widely studied by leadership researchers to date—the dynamic relationship between the psychological and spiritual domains in shaping the dark side, which lead to leadership failure and derailment. This book calls for a more interdisciplinary approach and holistic understanding of the dark side of leadership, inseparably relating body, soul, and spirit as they function individually and relationally. It highlights the fact that the restoration of personality will require sustained dialogue between theologians and the medical and psychological professions. Such a theoretical perspective would help us better understand how personality disorders develop, not only emotionally and psychologically, but spiritually.