Depression is a very common emotional component that can occur in all people. When people encounter mental stress, life frustration, painful situations, old age, sickness and death, natural and man-made disasters, it is only natural that they will become depressed. But depression is different, it is a pathological psychological depression disorder, completely different from the depression that occurs after encountering frustration, if you encounter unpleasant things and do not produce depression, that is abnormal. How to distinguish normal depressive mood from pathological depression? 1, normal people’s mood depression or melancholy is based on certain objective things, things happen for a reason. In contrast, pathological depressive disorder usually arises for no reason, lack of objective mental stress conditions, or although there are adverse factors, but “trivial”, not enough to really explain the pathological depressive signs. 2, the general mood changes have a certain time frame, usually short-term, people usually through self-adjustment, give full play to the function of self-defense, can restore psychological stability. In contrast, pathological depressive symptoms often persist, and even difficult to alleviate on their own without treatment, and the symptoms will gradually worsen. Psychiatry stipulates that general depression should not exceed two weeks, if it exceeds one month, or even lasts for several months or more than six months, then it is definitely pathological depression symptoms. 3, the general degree of depression is mild. The degree of depression is serious, and affects the patient’s work, study and life, unable to adapt to society, affecting its social function, and even produces serious negative, suicidal words and actions. 4, depression can be recurrent, the basic symptoms of each episode is roughly similar, with previous medical history can be confirmed. 5.Typical depression is characterized by biorhythmic changes, showing a pattern of morning heavy and night light changes. Many patients often say that their mood is particularly bad and painful in the early morning, so many patients often have suicidal thoughts at this time. After 3-4 p.m., the patient’s state of mind gradually improves, and in the evening, it seems to feel no more problems, and the next morning, they fall into a morbid and difficult time. 6, depression in the family often has a history of psychosis or similar episodes of affective disorders. 7. There is persistent intractable insomnia, simultaneous blocked inhibition of multiple psychological behaviors, low physiological function, decreased instinctive activity, decreased weight, appetite and libido, and functional discomfort in multiple areas of the body that are difficult to locate and characterize, and no abnormalities on examination, all of which are common signs of depression. The diagnosis of depression should be based on medical history, clinical symptoms, course of the disease, physical examination and laboratory tests, and the diagnosis of typical cases is generally not difficult. Close clinical observation, grasping the main symptoms of the disease cross-section and the characteristics of the longitudinal course of the disease, and conducting scientific analysis are the reliable basis for clinical diagnosis. One must not match various symptoms with oneself and engage in self-torture.