Depression is mainly characterized by depressed mood, slowed thinking and reduced volitional behavior, and if at least four of the following symptoms are present during this period and persist for more than two weeks, it is recommended to seek medical treatment. 1, the degree of depression varies, from a mild state of mind to sadness, pessimism, despair. Patients feel heavy, life is not meaningful, happy, depressed, spending time like a year, painful, can not allocate themselves. Some patients can also appear anxious, easily agitated, nervous and anxious hopeless feeling. 2.Loss of interest is one of the common symptoms of depressed patients. Loss of enthusiasm and pleasure in life and work, and loss of interest in everything. The patient does not experience the joy of family, does not care about the past hobbies, often lives alone behind closed doors, alienates friends and relatives, and avoids social life. Patients often complain of “no more feelings”, “emotional numbness”, “no more joy” and a sense of boredom. 3. Loss of energy, fatigue and weakness, difficulty in washing, dressing and other small tasks of life, and inability to cope with them. Patients often use the words “mental breakdown” and “deflated ball” to describe their powerlessness. 4. Low self-evaluation: Patients tend to excessively depreciate their own abilities, and view their present, past and future in a critical, negative and negative manner, saying that they are useless and that their future is dark. Strong self-blame, guilt, and, in severe cases, self-guilt, feelings of uselessness, worthlessness, and helplessness can occur. 5, the patient is a significant, persistent, general depressive state, attention difficulties, memory loss, slow brain, closed mind, slow action, but some patients are manifested as restlessness, anxiety, tension and agitation. 6, negative pessimism: very painful, pessimistic, despair, feel that life is a burden, not worth staying, to die for relief, may produce strong suicidal thoughts and behavior. 7, physical or biological symptoms: depressed patients often have a loss of appetite, weight loss, sleep disorders, low sexual function and mood fluctuations around the clock and other biological symptoms, very common, but not in every case: 8, loss of appetite, weight loss: most patients have a loss of appetite, poor appetite symptoms, delicious food is no longer tempting, patients do not think of tea and rice or tasteless, often accompanied by weight loss. 9, sexual hypogonadism: early in the disease can appear to reduce sexual desire, men may appear impotent, female patients have sexy loss. 10.Sleep disorder: The typical sleep disorder is early awakening, 2 to 3 hours earlier than usual, not going back to sleep after waking up, and falling into a sad atmosphere. 11.Diurnal variation: The patient’s mood has the variation of heavy day and light night. Early in the morning or in the morning, they fall into a low mood, and in the afternoon or evening, they gradually get better and can have a short conversation and a meal. The incidence of diurnal variation is about 50%.