Mental health disorders have become one of the most significant public health concerns among adolescents and young adults worldwide. This developmental period is characterized by profound biological, psychological, and social changes that may increase vulnerability to mental health problems. Disorders such as depression, anxiety, eating disorders, substance use disorders, and behavioral disturbances can significantly affect academic performance, social relationships, and overall quality of life. If left untreated, these conditions may persist into adulthood and contribute to long-term disability. This article explores the epidemiology of mental health disorders among adolescents and young adults, examines major risk factors, discusses preventive approaches, and reviews current treatment strategies aimed at improving mental well-being and long-term outcomes.