Depression is one of the most common psychological disorders today. Its incidence has been on the rise in recent years in countries around the world. Depression is mainly characterized by depressed mood, slowed thinking and reduced volitional activity, and most cases also have various physical symptoms. 1, depressed state of mind: the basic characteristics are depressed mood, distress and sadness, interest is not. Feeling pessimistic and desperate, painful and unbearable, with the feeling that life is like a year and life is worse than death. The inner experience is often described as meaningless and unhappy. The typical person has a depressed mood, with heavy daytime and light nighttime. It often coexists with anxiety. 2. Delayed thinking: the thinking association process is inhibited, the reaction is slow, and the brain is not spinning consciously, which is manifested by the reduction of active speech, the speed of speech is significantly slowed down, and the thinking problem is laborious. Slow reaction, need to wait a long time, under the influence of low mood, low self-esteem, low self-esteem, a sense of uselessness and worthlessness, feeling that living is meaningless, pessimistic and suicidal intentions, self-blame and self-sin, think that living becomes a burden, committing a big crime, on the basis of physical discomfort, the emergence of the concept of hypochondriac, think they are suffering from an incurable disease. 3. Decreased volitional activity: active activities are significantly reduced, life is passive, reluctant to participate in the outside world and activities that are usually of interest, and often solitary. Life is lazy and develops into silence and immobility, which can reach the level of rigor mortis. The most dangerous thing is the recurrence of suicide attempts and behaviors. 4.Somatic symptoms: Most depressed patients have physical and other biological symptoms, such as palpitations, chest tightness, gastrointestinal discomfort, constipation, loss of appetite and weight loss. Sleep disorders are prominent, mostly difficulty in falling asleep. 5. Others: Depressive episodes can also present with hallucinations, depersonalization, dissociation of reality, obsessive-compulsive and phobic symptoms. Because of the significant delay in thinking association and memory loss, it is easy to affect the cognitive function of elderly patients and appear depressive pseudo-dementia. Mild depression often has complaints of dizziness, headache, weakness and insomnia, and is easily misdiagnosed as neurasthenia. The latter has certain psychosocial factors before the onset of the disease, such as long-term tension, overuse of the brain, etc. The emotions are mainly anxiety and vulnerability, and the main clinical phases are emotional symptoms such as mental fatigue, tension, worry and irritability associated with mental arousal, and symptoms of physiological dysfunction such as muscle tension pain and sleep disorders. The self-knowledge is good, the passivity of symptoms is high, and the desire to seek treatment is high. In contrast, depression is mainly depressed mood, accompanied by slow thinking, low self-esteem, self-crime, desire to die, and biological symptoms (such as light mood around the clock, decreased appetite, libido, etc.), and often loss of self-awareness, not actively seeking treatment, which can be distinguished. Occult depression is an atypical depression, mainly manifested by recurrent or persistent various somatic discomfort and vegetative symptoms, such as headache, dizziness, palpitations, chest tightness, shortness of breath, numbness of the limbs and nausea, vomiting and other symptoms, depressed mood is often masked by physical symptoms, so it is also called depressive isotonic disorder. Patients often do not seek psychiatrists but go to other departments. Somatic examination and ancillary tests are often not positive, and are easily misdiagnosed as neurosis or other somatic diseases. Symptomatic treatment is generally ineffective, and antidepressant treatment is effective.