At present, social competition is becoming increasingly fierce, and almost everyone is overloaded in their own work sphere, which can easily produce different degrees of depression, which is a very common social phenomenon. When people encounter work pressure, life frustration, painful situations, natural or man-made disasters, the emergence of depression is a normal psychological reaction. At some point in our lives, we may be depressed at a certain time or in a certain situation. However, persistent and severe depression is a different matter. People are unable to distinguish between depression and depression. As the old saying goes, “Life is not as good as it should be.” In the current increasingly competitive society, almost everyone is overloaded, and it is easy to have different degrees of depression, which is a very common social phenomenon. 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. Having depressive manifestations or experiences does not necessarily mean that one is depressed. However, there are also people who mistakenly think that depression is just a depressed mood. What exactly is the difference between the two? What does a normal depressed mood look like? Mainly from the following aspects for comprehensive consideration: 1, time: normal people’s depressed mood generally does not last long and is transient; 2, degree: depressed people’s depressed mood symptom group is very serious, affecting the patient’s social function; 3, triggering causes: normal people’s depressed mood is based on certain objective things, things happen for a reason. Depression, on the other hand, is pathological mood depression, which usually arises for no reason, or although there are adverse factors, however, is not enough to truly explain the pathological depressive signs. The etiology of depression has not been fully elucidated, but it is certain that many biological (genetic, neurobiochemical, neuroendocrine, neuroregenerative, etc.), psychological (premorbid personality traits such as depressive temperament) and social environmental (stressful life events in adulthood) factors are involved in the pathogenesis of depression. Among them, the exposure to stressful life events in adulthood is an important trigger for the development of clinically significant depressive episodes. Currently, it is emphasized that the interaction between genetic and environmental or stressful factors, as well as the point at which such interaction occurs, has an important influence in the development of depression. Depression affects only a subset of people. Therefore, do not apply the symptoms of depression to yourself to avoid unnecessary psychological burden, but also do not blindly use life events to explain the symptoms of depression, which can delay the treatment of depression and even lead to tragedy.