Depression is a common psychiatric disorder that can be caused by a variety of reasons, with significant and persistent depression as the main clinical characteristic, and the depression is not commensurate with its situation, and in severe cases, suicidal thoughts and behaviors can occur. Most cases have a tendency to have recurrent episodes, with most episodes resolving, and some may have residual symptoms or become chronic. The most critical core symptom of depression is depressed mood, which must last for more than two weeks. Early depression is characterized by mild depressed mood, manifesting as fretfulness, and gradual mood changes from a poor mood to sadness, even despair, or even suicide, with a gradual loss of confidence in life. Some patients are often accompanied by anxiety, and may also be accompanied by symptoms such as weakness, less speech, less food, and memory loss. Depression is a preventable and treatable mental illness, and can be cured clinically as long as it is detected and treated in a timely manner.