This practically relevant textbook provides valuable assistance for teaching in classrooms where children and adolescents with low motivation, inefficient learning, and emotional and behavioral issues are increasingly present. This guide describes theoretically and empirically grounded knowledge that can help professionals effectively address these problems in their work. Following an introduction to psychological schools and psychotherapy theories, foundational research on motivation and learning and their practical implications is presented. Subsequently, findings on issues that are highly relevant in the classroom, such as ADHD, depression, anxiety/test anxiety, eating disorders, or aggression/bullying, are clearly explained. Based on this, it is outlined how teachers can support their students.