People may wonder: society has progressed, how come the number of mental illnesses has increased? This is true. The disparity between the rich and the poor, the huge pressure of study and work, and the difficulty of employment are many social factors that bring a lot of negative effects on people’s psychology. Among them, depression is the killer disease of modern society. According to the American psychologist Speeler’s survey: “This disease tends to attack those who are the most ambitious, the most creative, and the most serious in their work”. Great men such as Isaac Newton, Darwin, Abraham Lincoln and Winston Churchill all suffered from depression. Princess Diana suffered from depression and attempted suicide several times. What about depression? If you know the core symptoms, it is not difficult to detect it! If you find depression, you should take it to a tertiary or specialized hospital as soon as possible. The symptoms of depression are as follows: 1. core symptoms: depressed mood 2. main symptoms: loss of symptoms – loss of interest, hopelessness, helplessness, loss of initiative, loss of self-confidence and self-esteem, loss of meaning in life 3. biological symptoms: psychomotor retardation, fatigue, sleep disturbances characterized by early awakening, changes in libido and appetite (mostly decreased), weight loss, decreased visceral function, autonomic Other accompanying symptoms: anxiety, hesitation and compulsion, hypochondriasis, psychotic symptoms, depersonalization, decreased attention and memory.