Book excerpt: Based on a decade of research and theory, Substance Use Disorders and Addictions examines co-occurring psychiatric disorders as the norm with substance use disorders and addictions. With more than 20 years of experience in the field as a clinician, a researcher, a program developer, and an instructor, Keith Morgen encourages a holistic approach to working with individuals, using a single case example throughout the text to encourage the sequential application of concepts to co-occurring disorders. With DSM-5 diagnostic criteria, the 2014 ACA code of ethics, and 2016 CACREP standards integrated throughout, readers will benefit from this applied and cutting-edge introduction to the field.