After we have a preliminary understanding of depression, we will have some questions in our mind, that is: How does depression happen? What causes depression? Many people believe that depression occurs because an individual is too introverted or has experienced unhappy events. In fact, this view is very one-sided and incorrect. To date, the exact cause of depression is not well understood by the medical community. However, the prevailing view is that depression is not caused by a single factor, but is related to many factors. A combination of genetic factors, social and environmental factors, personality traits, one’s own endocrine function, brain function and other factors ultimately lead to depression. Let’s understand the impact of these factors on the development of depression separately. 1, genetic defects: research has found that genetic factors have an important role in the development of depression, the risk of disease in the families of depressed patients is significantly higher than the general population, and their chances of developing depression are 10 to 30 times higher than the general population. The closer the blood relationship to the patient, the higher the probability of developing the disease. However, the exact mode of inheritance is very complicated, and it is not the usual belief that “if the elders in the family do not have depression, the younger generation will not suffer from depression”. Genetic factors only mean that there is a higher tendency and probability of depression, but not that children of parents with depression will definitely get depression. 2, social environment factors: In fact, the relationship between what we encounter in life and the occurrence of depression is not very clear. However, many scientists now believe that depression can be triggered by stressful life events, such as widowhood, especially in old age, divorce, loss of job, financial crisis, loss of health and so on. In addition, a highly competitive society may also be a psychosocial factor that leads to depression. 3, individual physiological defects: the basis for the occurrence of depression may be related to the disorder of metabolism of some chemicals in the brain of patients. Abnormalities in the function and metabolism of certain neurotransmitters in the central nervous system of such patients may be the cause of depression. Psychologists use drugs to treat depression by regulating these neurotransmitters to achieve the purpose of treatment. 4, physical diseases: many chronic central nervous system diseases or other chronic physical diseases may be important risk factors for depression, such as malignant tumors, hypothyroidism, Parkinson’s disease, epilepsy, etc.. The specific causative factors are not well understood. Older people often suffer from a variety of chronic diseases, so many elderly patients with chronic diseases are often accompanied by depression. 5, personality characteristics: depression and people’s personalities are closely related. Some people are big-hearted and do not store things in their hearts, so these people are generally less likely to have depression. Usually two types of people are more likely to get depression. One is introverted, low self-esteem, sentimental people, such as Lin Daiyu itself is a depressed character, all day sentimental, sad, sad, everything to the bad, often trapped in low self-esteem, self-blame, pessimism; the other is too strict, the pursuit of perfection, these people are serious about everything, the pursuit of perfection, self-esteem is very strong, almost demanding on their own, conservative thinking, difficult to adapt, do not allow They do not allow themselves to make mistakes. People with this personality trait are difficult to get rid of once they have been failed and frustrated, which is why many people with excellent quality and great achievements finally choose to commit suicide. 6, endocrine changes: the number of women suffering from depression is about two times that of men, and the onset of depression in women has three peaks: one is a few days before menstruation, the second is before and after childbirth, and the third is the female menopause. During these three periods, women’s hormone levels change significantly, and many women experience depression and anxiety during this period. For example, foreign surveys show that about 30% of women suffer from different degrees of depression after childbirth. It can be seen that the occurrence of depression is also closely related to the endocrine metabolism in the human body. In general, depression develops under the combined effect of several factors mentioned above, and the role of these factors in the development of depression is not the same for different patients. For some patients, the main cause of the onset of depression is more related to genetic defects, while in others the disease may be associated with adverse external environmental factors. To determine the cause of a depressive disorder more accurately, an experienced clinician needs to analyze the patient’s specific situation and not to make generalizations.