Specifically, he addresses the theory of "harm reduction," which apparently tends to get short shrift in the US. If you work in public health, you may be familiar with this interventional modality, but as a student who went from school right into critical care, I don't ever remember hearing the term before this book. Harm reduction is a recognition that quitting addictive substances is extremely hard, and that it may be more productive to get users to change behavior related to their addictions rather than stop. In alcoholics, this might entail designated driver campaigns, while in IV drug users, it might entail needle exchanges. Simple ideas that have been tried in teh US before, but the presentation of a paradigmatic interventional strategy puts these programs in a different light and suggests others.
The book is not only about harm reduction, however. It also has chapters that can be used like a workbook to challenge the reader's assumptions about addiction and addicts. And it presents information on professional matters as well as outlining current interventional strategies for a variety of substances and summarizing the research on the effectiveness of these strategies. I had never heard of Motivational Interviewing or Brief Interventions before, either, but both are shown to work with equal or greater effectiveness compared to 12-step programs.
This is a great book for nurses to read, I think. Much of it is available as a preview at GoogleBooks.