Depressive disorder in children and adolescents represents a growing public health concern, with its prevalence rising annually. Characterized by complex etiologies and significant functional impairment, untreated depression in this population can lead to chronic mental health issues in adulthood, presenting substantial challenges to both clinical services and public health systems. While the causes are often understood within a biopsychosocial framework, the unique developmental stage of childhood and adolescence introduces specific risk factors distinct from those seen in adults. This article reviews the multifactorial etiology of pediatric and adolescent depression, aiming to inform early screening and precision prevention efforts, and to guide developmentally appropriate intervention and treatment strategies.