Depression is a disease that endangers the physical and mental health of all human beings. According to statistics, depression can be diagnosed in 22% to 33% of patients hospitalized in internal medicine. Some patients with chronic diseases such as heart disease, cancer, lung disease, and stroke have a significantly higher rate of depression. Cardiovascular disease and depression: Surveys show that 40% of patients with coronary heart disease and 45% of patients with myocardial infarction have concomitant depressive symptoms. Depression will significantly reduce the patient’s compliance with cardiovascular disease treatment and greatly affect the recovery process of the disease. More seriously, depression can precipitate myocardial infarction and increase long-term mortality from cardiovascular disease by more than 80 percent. Stroke and depression: Two-thirds of stroke patients experience depressive symptoms in the two years following the onset of the stroke. Studies have shown that concomitant depression will triple the mortality rate in stroke patients. Depression will significantly reduce the stroke patient’s desire for active recovery, thereby delaying neurological recovery, as evidenced by decreased speech, motor, and walking abilities. Diabetes and depression: It is well documented that one-third of people with diabetes suffer from depressive symptoms while undergoing treatment. Depression greatly affects the glycemic control process of diabetic patients and can lead to an increased risk of chronic complications such as retinopathy, coronary artery disease, stroke, and renal failure. Tumor and depression: Information shows that nearly half of the tumor patients are accompanied by depression. Depression will lead to the decrease of muscle immune function and aggravate the existing pain. Depression will make patients fall into lasting pain, lack of confidence to overcome the disease or pessimistic thoughts about the prognosis of the disease. Long-term studies have shown that depression can reduce the survival rate of oncology patients by 20%.