Schizophrenia is a kind of chronic mental disorder that leads to disability, and it is characterized by the incoordination of perception, mind, emotion and behaviour, and the disconnection between mental activities and reality. It is recurrent and hard to cure. Schizophrenia has caused both agony to patients and their families, and heavy economic burden to their families and society. The appearance of chlorpromazine, the first antipsychotic drug in the 1950s, brought about a revolutionary change in the treatment of schizophrenia. Even though the first-generation antipsychotic drug’s effectiveness for schizophrenia (especially the positive symptoms) was absolutely positive, it did not cause significant improvement in negative symptoms or cognitive impairment. Furthermore, these drugs could cause a variety of adverse reactions, such as extrapyramidal side effects, oversedation and so on. Therefore, a number of second-generation antipsychotic drugs gradually appeared on the market in the 1970s. Compared to the first-generation drugs, they were less likely to cause those side effects. In the meantime, some randomised controlled trials reported that the effectiveness of the second-generation antipsychotic drugs during the acute stage treatment of schizophrenia was significantly better than that of the first generation. Hence, a lot of hope was put into the second-generation antipsychotic drugs within the field of clinical psychiatry. However, as the drugs became more widely used, it was found that their long-term effect did not reach the expected level in many clinical observations and studies. In order to eliminate the pharmaceutical companies’ conflicts of interest in evidence-based medical studies, the National Institute of Mental Health granted a total of US$40 million funding to carry out the Clinical Anti-psychotic Trials of Intervention Effectiveness (CATIE) study in 57 centres of 24 states in the USA in 2005.1 According to the results of CATIE, there were no differences in the effectiveness of the second-generation antipsychotic drugs and perphenazine, the …