Depression is a type of mental disorder with depressed mood as the main symptom caused by various reasons. Its core manifestations are depressed mood, decreased or lost interest and enjoyment, and decreased energy leading to increased fatigue and reduced activity, in addition to common symptoms such as sleep disturbance, difficulty in paying attention, decreased self-confidence, self-blame, and suicidal thoughts and behaviors. Yi-Fa He, Department of Psychiatry, Shanghai Mental Health Center