Adolescent depression is an early-onset affective disorder with recurrent episodes, the duration of which depends on the severity of the illness, the individual’s physical condition and other aspects and cannot be generalized. In mild cases of adolescent depression, patients only experience depressed mood, reduced interest, pessimism, and slowed thinking, which are usually short-lived and may improve in a few months through psychological or physical treatment. If the condition is more severe, patients may experience significant mood swings, irritability, anxiety, aggressive behavior, etc. Depression usually lasts longer and has an impact throughout adolescence or adulthood, and patients need medication to improve negative and depressive moods. Therefore, the duration of adolescent depression varies from person to person. Patients with adolescent depression can get more outdoor exercise in their daily life and maintain a regular routine. Parents need to communicate more with their children to identify the dangers early and help them improve their depressed mood as soon as possible.