Adolescence is an important stage of development marked by quick changes in the brain and emotions. During this time, young people become more vulnerable to mental health issues. Taking part in organized sports can help build resilience, social connections, and self-esteem; however, new evidence shows that it might also create psychological stress. This review looks at mental health outcomes in adolescent athletes aged 12-19, based on peer-reviewed studies published from January 2000 to December 2025. We included and summarized 45 studies using a biopsychosocial and ecological approach to find key risk factors, protective mechanisms, and intervention strategies. The findings indicate that adolescent athletes face a variety of mental health challenges, such as anxiety, depression, burnout, and disordered eating. Reported rates indicate higher levels of anxiety (about 40-50%), disordered eating (up to 42% in aesthetic sports), and burnout (35-45% in endurance sports), while lower rates of anxiety and depression are seen in team sports (around 10-20%). Common risk factors include performance pressure, fear of failure, early specialization in sports, overtraining, injury-related identity changes, unhealthy perfectionism, controlling coaching styles, and body image issues. On the other hand, protective factors include supportive coaching, a strong team environment, family support, a balanced athletic identity, and good coping skills. In summary, organized sports can both pose risks and offer protection for young people's mental health. This underscores the importance of developing comprehensive prevention and intervention strategies.