When the cause of any disease is found, treatment may become easier, but unfortunately the cause of most diseases is not known. This is also true for the etiology of mental illness. Although some progress has been made in the etiology of schizophrenia as scholars have invested heavily in etiological research and high-tech research tools have been applied in large numbers, it has not been fully elucidated to date. Possible relevant factors are: 1. Genetic factors There is more evidence that schizophrenia is hereditary, with a much higher prevalence among patients’ family members than among the general population, and the more advanced the blood relationship, the higher the prevalence. Family lineage survey studies have found that the prevalence of psychosis among family members of schizophrenia patients is 6 or 2 times higher than that of the general population. The prevalence of schizophrenia in children of parents with both parents is 35%-68%, compared to 0.38%-0.84% in the normal population. 2, psychosocial factors 1) family environment: there are reports that more schizophrenia patients live in broken families (parental divorce, death or runaway) during early childhood; more patients have parents with strange personalities or neuroses; more parents have abnormal relationships with their children, etc. 2) Personality problems: Many schizophrenic patients have a bad personality before the illness, such as a schizophrenic-like personality. (3) Life events: Certain life events can indeed influence the appearance of symptoms, but it is not clear whether the life event is the cause or the effect. For example, after the 9/11 attacks, 400,000 New Yorkers had varying degrees of mental disorders, but many more did not have mental abnormalities. 3, biological factors The most important etiological study of schizophrenia, but also the clinical treatment is most proud of the antipsychotic drugs, but not first the etiological study, and then the treatment, the first antipsychotic drug chlorpromazine on the treatment of schizophrenia was discovered purely by accident, and then the understanding of the disease has made a breakthrough, and now all the development of antipsychotic drugs are in chlorpromazine The foundation was started. The doctrine underlying the development of antipsychotic drugs is the “dopamine hyperfunction doctrine”! Other neurotransmitters such as r-aminobutyric acid, glutamate and neuropeptides have also been the focus of research in recent years. 4. Other maternal severe malnutrition, viral infection during pregnancy and perinatal brain injury, the role of neurodevelopment and damaged synaptic plasticity may all play a role in the development of schizophrenia. In summary, although the etiology of schizophrenia has not yet been elucidated, some progress has been made and most patients with first-episode schizophrenia are effectively treated, but relapse of schizophrenia is another issue worth discussing, see my article “Factors affecting the prognosis of schizophrenia”.