The primary focus of this book is to examine the use of the opiate antagonist naltrexone as a safe and effective treatment for opiate dependency. This book consists of theory and research papers and protocols written over the past 10 years to communicate the results of my work for training and instruction of practitioners and to the wider community to promote the effective use of naltrexone. Importantly, the book provides the evidence for the optimal use of naltrexone based on my clinical experience treating opiate dependent people. In addition to naltrexone, I believe a broad multi-disciplinary approach is essential to effectively treat a complex and seemingly intractable problem. The book includes my concept of addiction, which is mainly attributable to structural changes in the brain caused by persistent behaviour or use of a substance. This theory guides the treatment approach adopted in the program. I also examine the pharmacology of naltrexone; review the literature on the use of naltrexone; and describe in detail the psychological approach and interventions that underpin the effective use of naltrexone.