The Chinese Classification and Diagnostic Criteria for Mental Disorders, Third Edition, defines the diagnostic criteria as a predominantly depressed mood, disproportionate to the situation, which can range from sullenness to grief and even malaise. In severe cases, psychotic symptoms such as hallucinations and delusions may occur. The three main symptoms: depressed mood, slowed thinking and motor inhibition. 1. Endogenous depression: the “five signs” of laziness, dullness, change, worry and anxiety (relative or absolute deficiency of biogenic amines in the brain). 2. Reactive depression is depression caused by various mental stimuli and frustrations. In life, people with poor mental ability to cope with sudden natural or man-made disasters, loss of love and marriage, serious illness, career setbacks, etc. are prone to reactive depression. 3.Hidden depression The symptoms of low mood and depression are not obvious, but often manifest as various somatic discomfort symptoms, such as palpitations, chest tightness, mid-upper abdominal discomfort, shortness of breath, sweating, wasting, insomnia, etc. 4, depression characterized by learning difficulties This type of depression can lead to learning difficulties, inattention, memory loss, overall decline or sudden decline in performance, anorexia, fear of learning, truancy or refusal to learn. 5, secondary depression caused by drugs, such as some hypertensive patients, after taking antihypertensive drugs, resulting in continued depression, depression. 6, secondary depression caused by physical diseases such as heart disease, lung disease, endocrine metabolic diseases and even heavy colds, high fever, etc., can trigger this type of depression. 7, postpartum depression It is characterized by strong guilt, low self-esteem (especially in rural women who have female babies and are discriminated by their mothers-in-law or husbands), hatred, dislike or aversion to the child’s perversity. Crying, insomnia, inability to eat, and depression are common symptoms of such depressed patients. 8, menopausal depression First onset in menopause, often with certain mental factors or somatic factors as the cause, mostly with the performance of menopausal syndrome, clinical symptoms are mainly anxiety depression, good intelligence. 9, depressive neurosis, also known as depressive neurosis, is a milder form of depression. It is manifested as a continuous state of depressed mood, often accompanied by many symptoms of neurasthenia, and its prognosis is better.