Schizophrenia is a group of severe psychiatric disorders of unknown etiology, most often with a slow or subacute onset in young adults, and often manifests clinically as a syndrome of varying symptoms involving multiple impairments in perception, thinking, emotion and behavior, as well as incoordination of mental activities. Patients are generally conscious and have normal intelligence, but some patients may develop cognitive impairment during the course of the disease. The course of the disease is generally prolonged, with recurrent episodes, exacerbation or deterioration, and some patients eventually experience decline and mental disability, but some patients can remain cured or basically cured after treatment. Clinical manifestations The clinical symptoms of schizophrenia are complex and varied, and can involve perception, thinking, emotion, volitional behavior and cognitive function. （The most prominent perceptual disorders are hallucinations, including hallucinations of hearing, vision, smell, taste and touch, and hallucinations of hearing are the most common. (2) Thought disorder Thought disorder is the core symptom of schizophrenia, mainly including thought form disorder and thought content disorder. Thought form disorder is mainly manifested by thought association process disorder, including thought association activity process (quantity, speed and form), thought association coherence and logic disorder. Delusions are the most common and important disorders of thought content. The most frequent delusions include delusions of victimization, delusions of relationship, delusions of influence, delusions of envy, delusions of exaggeration, and delusions of nonancestry. It is estimated that up to 80% of patients with schizophrenia have delusions of victimization. Delusions of victimization can manifest as varying degrees of insecurity, such as being watched, rejected, fear of being drugged or murdered, etc. Under the influence of delusions, patients may engage in defensive or aggressive behavior. In addition, passive experiences are more prominent in some patients and have an impact on their thinking, emotions and behavior. (3) Affective disorders Affective indifference and incoherent emotional responses are the most common affective symptoms in patients with schizophrenia. In addition, affective symptoms such as incoherent arousal, irritability, depression and anxiety are also more common. (4) Will and behavior disorders Most patients have a reduced will or even lack of will, which is manifested by reduced activity, isolation, passive behavior, lack of proper motivation and initiative, diminished interest in work and study, lack of concern for the future, and no clear plan for the future. (5) Cognitive deficits The incidence of cognitive deficits is high in patients with schizophrenia, and about 85% of patients show cognitive deficits, such as information processing and selective attention, working memory, short-term memory and learning, and executive function. There is some correlation between cognitive deficit symptoms and other psychotic symptoms, such as cognitive deficit symptoms are more pronounced in patients with significant thought form impairment, cognitive deficit symptoms are more pronounced in patients with significant negative symptoms, and cognitive deficits may be associated with the production of certain positive symptoms. Cognitive deficits may occur before psychotic symptoms become explicit (e.g., prodromal phase), or they may decline sharply with the onset of psychotic symptoms, or they may decline gradually with the prolonged course of the illness, and it is tentatively believed that cognitive deficits are more pronounced in patients with chronic schizophrenia than in patients with first-episode schizophrenia. Numerous studies have been analyzed to show that genetic factors play an important role in the development of schizophrenia. Results from foreign studies have shown that the relative risk of the disease in children of both parents with schizophrenia is 60%. Studies of schizophrenic family lines have shown that the prevalence is significantly higher among relatives than among the general population, and the closer the blood relationship to the patient, the higher the prevalence. The prevalence of schizophrenia in the population is around 1%, while it can be as high as 13% in the offspring of schizophrenic patients. Even among twins living in different family environments, monozygotic twins with nearly identical genetic information have a higher rate of homozygosity than dizygotic twins with less than identical genetic information, with a prevalence consistency of 56.7% on average for homozygotic twins, which is 4.5 times higher than the rate of heterozygotic twins (12.7%) and 35-60 times higher than the rate of homozygosity in the general population. A survey of foster children found that the incidence of schizophrenia was higher among blood relatives of patients who grew up in foster care and developed schizophrenia as adults than among normal controls, whereas the incidence among relatives of foster families was similar to that of normal controls. Schizophrenia is a polygenic genetic disorder, and the study of genes related to its pathophysiological processes and the analysis of the correlation between relevant gene polymorphisms and schizophrenia may provide some basis for the study of the etiology of schizophrenia and the search for new methods of treatment.