I. Introduction
Teenagers are in a high incidence of depression, and many adolescents will suffer from depression due to psychological immaturity or other problems. However, parents often think that not giving children a good life is the result of intentional truancy, which may affect the development of adolescent patients. At least 20 percent of teenagers experience depression, and research shows that girls are more likely to suffer from depression than boys. For the health of adolescents, people should clearly know the symptoms of depression, timely detection of the disease and treatment. The diagnosis of major depression requires significant mood changes, marked by sadness or irritability and accompanied by at least several psychological and physical variations, including sleep, appetite, or libido disorders, constipation, losing the ability to have fun at daily life, weeping, suicidal thoughts, speaking as well as acting slowly. These changes, which last at least two weeks, must have a considerable impact on work and family relationships of adolescents. Therefore, the author focuses on the causes and treatment of adolescent depression in order to provide some suggestions.