The basic manifestation of depression is a low mood. In layman’s terms, it means a bad mood. It is inevitable that normal people sometimes have a bad mood, so what kind of depressed mood can be diagnosed as depression? To diagnose depression, 2 criteria must be met: (1) Severity: The depressed mood must be so severe that it is distressing and almost impossible to repel. The degree to which the depressed mood interferes with the patient’s psychological or social functioning (e.g., school, work, housework, social interaction, etc.); (2) Duration of the illness: The above-mentioned conditions occur daily and persist for at least 2 weeks. People who are highly educated or introspective and not ashamed of their psychological problems tend to be straightforward about their bad moods and can take the initiative to be vivid and specific; these people are more likely to be identified by physicians as suffering from depression. More patients, for various reasons, do not talk about their moods but only complain about their physical symptoms, which requires physicians to pay attention not only to the patient’s body, but also to their spiritual life and inner experience, and to master the knowledge about depressive symptoms and the special skill of asking good questions. Only in this way can the truth about depression be clarified. There are six main manifestations of depressed mood. The physician can talk to the patient around each of them. 1. Decreased interest or even loss of interest: People who have a wide range of hobbies can easily be noticed by people around them once they are depressed. However, even if there is no hobby, if the daily work, life enjoyment and family fun are all uninteresting and unhappy, it is certain that there is a significant decline or loss of interest. 2.Sense of hopelessness: The patient feels that everything is bad for the individual, the future is bleak, and everything is hopeless. In contrast, normal people have hopes for the future, such as academic progress, career success, and a long and healthy life for their family members; they also often have various small wishes, such as saving money to buy a piece of high-end goods, enjoying a beautiful music, and going out on a weekend trip for the whole family. Loss of hope for the future is a manifestation of depression. 3.Sense of helplessness: This feeling is very painful, especially the patient is difficult to express. Many patients do not want to go to the doctor, they are sure that the physician can not help, because he feels different from all other people, as if he has left the world, fallen into the bottom of the mountain, everything is irreparable, no one can save. The patient feels that his days are like years, and that he is lonely and alienated from others. 4. Decline in self-evaluation: The patient feels that he or she is actually incapable of doing anything and is a complete waste. At the very least, the patient feels that his or her intellectual abilities are not what they used to be. Some patients have a deep sense of guilt or even guilt. 5. Loss of vitality: The patient feels that his whole “person” has collapsed, crumbled, and fallen apart. It is clear that the main problem is not a lack of physical strength, but a loss of mental motivation, and that he needs to be urged or pushed to do anything (including self-care), otherwise he does not want to move at all. Many patients struggle to get up, but they can’t keep going. Patients believe that they have become “a puddle of mud – can not be helped up.” 6, feel that life has no meaning: patients do not feel that a certain way of life has no meaning, but that life is fundamentally meaningless. Not only is there no meaning, living is the same as suffering and sins, life is worse than death. Patients often have suicidal thoughts, and even implement suicidal measures. As long as any of the above six are obvious or prominent, we have to think of the possibility of depression. Depression is a syndrome and certainly has more than one symptom, but a certain symptom can be less obvious. If it is suspicious but difficult to diagnose, a psychiatric consultation must be requested.