Depression occurs in children and adolescents far more frequently than previously thought. It manifests in symptoms such as sadness, despondency, lack of motivation, and withdrawal, often leading to suffering and daily limitations for young people and their families. Depression poses a serious developmental risk if the disorder is not recognized and treated appropriately at an early stage. This book provides a clear and practical overview of the increasingly complex knowledge about depression in childhood and adolescence. It describes different forms of depressive disorders, presents current findings on the prevalence and course of these disorders, and introduces various explanatory approaches. Additionally, it offers practical diagnostic options and promising treatment strategies.