Book excerpt: Trauma, trauma-related disorders, substance use, and addictive disorders often co-occur, and frequently play a role in the problems and issues that social workers contend with in their practice with individuals, families, and communities. Research shows that there is a relationship between trauma-related symptoms and problematic use of substances and other addictive behaviors. Individuals who experience these co-occurring problems have better outcomes when their issues are addressed with integrated treatment approaches. Trauma-informed care and trauma-specific treatment are therefore important components of effective social work interventions. This book examines various types of trauma, such as intergenerational trauma, adverse childhood events, childhood sexual abuse, and minority stress, amongst various populations and settings, including Native Americans, homeless youth, drug court participants, and LGB adolescents. It also explores the challenges in delivering trauma services in outpatient addiction treatment settings. Furthermore, it provides practical information on how to implement trauma-informed approaches in addiction treatment, and offers insights into the experience of a trauma survivor who is also recovering from a substance use disorder. This book was originally published as a special issue of the Journal of Social Work Practice in the Addictions.