Elderly people with Alzheimer’s disease who do not sleep at night belong to the symptoms of the middle and late stages of Alzheimer’s disease, which are organic mental disorders. Patients have sleep disorders that lead to increased sleep during the day and reluctance to sleep at night, and are also accompanied by hallucinations, delusions, irritability, anxiety, depression, etc. At this time it is recommended to give antidepressants and antipsychotics for treatment. Antidepressants are currently more commonly used as paroxetine, escitalopram oxalate, sertraline or fluoxetine. Antipsychotics, on the other hand, are recommended as atypical antipsychotics, such as quetiapine, risperidone, and olanzapine. The principle when medication is administered is recommended to start with a low dose, gradually and slowly increase the dose and maintain it with the smallest dose that can control the patient’s symptoms, with a slightly longer interval recommended for each dose increase, at least once every 3-5 days. At the same time, we should pay attention to the patient’s underlying disease, and pay attention to whether there is any interaction between the medication the patient was using and the newly added medication.