A few days ago, when consulting, I saw such a case, an elderly brain atrophy patients appeared to be excited, behavioral disorders and noisy sleeplessness, the application of sleeping medication is ineffective, the use of antipsychotic drug treatment. The patient was treated with antipsychotic drugs, and the drugs were changed several times due to adverse reactions. From this, I thought of the problem of medication for psychiatric disorders in the elderly. The first psychiatric disorders in old age are mostly due to organic causes. The common ones are cerebrovascular disease (cerebral hemorrhage, cerebral infarction, etc.), Alzheimer’s disease, and Parkinson’s disease. In addition to physical symptoms, mental symptoms such as anxiety and depression, hallucinations and delusions, and confusion (excitement, noise, behavioral disorders and sleep disorders) are also common. In addition to anxiety and depression, these psychiatric symptoms are sometimes treated with antipsychotic drugs. Of course, the principle of not using antipsychotics for organic brain disorders is to minimize the use of antipsychotics, but when the patient’s psychiatric disorders seriously affect the patient’s health and interfere with the treatment of the primary disease, intervention is also warranted. The choice of antipsychotics should be based on the principle of small adverse effects and low dose. Because of the decline of the function of the organs of the elderly, the tolerance of adverse drug reactions decreases, and it is very easy to have adverse reactions and delay treatment. There are two broad categories of antipsychotics, traditional antipsychotics and new antipsychotics. The representatives of traditional drugs are haloperidol, chlorpromazine, and phenazopyridine. This kind of drug is characterized by the easy development of Parkinson’s syndrome, which is manifested by muscle stiffness, difficulty in walking, and limb tremor. Elderly people have organic brain changes and are very sensitive to these drugs. The elderly patient mentioned at the beginning of the article had these symptoms and they were so severe that he had to be taken off the medication. Newer antipsychotics are represented by clozapine, but this drug is not preferred due to its severe effects on hematopoiesis, blood pressure, blood sugar and heart. Risperidone, olanzapine and quetiapine are commonly used. These drugs are characterized by a much smaller effect on muscle tone than the traditional drugs and are suitable for use in the elderly. However, the effects on dystonia are not completely absent, and the elderly person mentioned above was taking a new drug. One of the drugs in this category that has less effect on muscle tone is quetiapine, which is an option. However, some people will experience postural hypotension when starting to use quetiapine, which means that the patient will easily become dizzy and fall down when changing positions, such as getting up, so it is important to start with a low dose (12.5mg/day or even lower) at the beginning of the use of quetiapine. In psychiatry, the individualization of medication is very prominent, some people use the same drug with very good results, others do not. The same goes for adverse effects. Here we focus on one aspect of the adverse effects, a drug has a variety of adverse effects, in the selection of drugs should be considered from various aspects.