The book is organized into nine sections of two to four chapters each. The first seven sections introduce specific vulnerable populations with a brief overview of their needs and a literature review. Each section ends with a description of the evidence-based and best practices for the treatment of the specific population. The populations covered include adults with severe mental illness and other disabilities, children, underrepresented sexual orientation groups, refugees, the elderly population, veterans, and people with criminal justice involvement. For each population emphasis is placed on trauma-informed care, reduction of stigma, cultural competence, and a systems approach to care.