Although some progress has been made in genetic and biochemical research on the etiology of schizophrenia, the current results are not sufficient to fundamentally address the pathogenesis of the disorder, and therefore it is not possible to determine the diagnosis in terms of etiology or pathology. The diagnosis is still based on clinical features, i.e., on clinical observations and descriptive psychiatric symptomatology. The correct diagnosis is often a process of continuous observation and understanding. It is precisely the evolution of the diagnostic criteria for schizophrenia in general. Wang Biao, Psychiatry Department, Shanghai Mental Health Center In 1896, Kraepelin of Germany, based on various specific clinical descriptions of this disease by his predecessors, collected clinical data of thousands of cases, analyzed the names and their various symptom clusters, considered them as different manifestations of the same disease, and proposed early-onset dementia with symptoms, course and prognosis as important features. He believes that the main feature of this type of patients is the destruction of the inner bonds of personality, which affects the emotional and volitional parts of mental life, and eventually often leads to the decline of reasoning and social interaction and dementia. The diagnostic concepts of early-onset dementia are: 1) loose and diffuse thinking, incoherent speech, which is difficult to understand; 2) inconsistency between emotions and thinking, emotions seem flat; 3) hallucinations; 4) loss of attention to the external environment; 5) lack of self-knowledge and judgment; 6) disobedience; 7) stereotyped behavior; 8) delusions; 9) clear consciousness and unimpaired memory. The concept of schizophrenia was first introduced by Swiss psychiatrist E Bleuler in 1911. It led to a substantial progress in the understanding of schizophrenia. In describing schizophrenic symptoms, E Bleuler distinguished between core symptoms and additional symptoms, and considered the core symptoms as association, apathy, amlivalencce and autism, which are the characteristic symptoms of schizophrenia. These are the characteristic symptoms of schizophrenia and have diagnostic significance. Additional symptoms include hallucinations, delusions, catatonia, and verbal behavior disorders, which are common but not characteristic. E Bleuler placed less emphasis on prognosis than on symptoms and their mechanisms of occurrence. In contrast, G Langfeldt’s diagnostic criteria emphasize prognosis, assuming that true schizophrenia (i.e., the core type) has no obvious etiology, is characterized by a schizoid personality before illness, and inevitably ends in decline. His concept of schizophrenia is relatively strict, with the characteristic symptoms being; severe impairment of self-boundaries, significant deficits in associative processes, and the experience of dramatic changes in oneself or the world around one. He proposed a limited number of characteristic symptoms, and the diagnosis could only be determined after 5 years, which affected the practical use. In order to improve the reliability of schizophrenia diagnosis, many scholars have studied the characteristics of schizophrenia. Inspired by E Bleuler’s work on schizophrenia and combined with his own clinical experience, K Sohneider proposed the first-order symptoms that are unique to schizophrenia but rare in other diseases, and suggested that schizophrenia could be diagnosed if patients had first-order symptoms and organic mental disorders could be excluded. K Sohneider’s first-level symptoms include 11 items, specifically 1, thinking sound (thinking sound); 2, argumentative hallucinations; 3, commentary hallucinations; 4, delusions of somatic influence; 5, thought seizure; 6, thought insertion; 7, thought diffusion; 8, thought broadcast; 9, imposed emotion; 10, imposed Will, impulse; 11 delusional perception. Among them, items 1 to 3 are characteristic hallucinations, the last one is delusion of special significance, and the others are controlled experiences of psychotic automatism, which are derived from patients’ complaints and have the advantages of easy identification and high reliability of clinical use. However, it is a major regret that Bleuler’s basic symptoms were not introduced into this system. However, K Sohneider pointed out that it is not necessary for every case of schizophrenia to have the first level of symptoms in order to make a diagnosis, which is very important in the diagnosis of schizophrenia and was most influential in the 1950s and 1960s. In particular, emotional disorders with psychotic symptoms are misdiagnosed as schizophrenia. According to domestic and foreign research, the rate of first-level symptoms in schizophrenic patients is 28% to 71.7%, and it is found that 1/10 to 1/4 patients in bipolar disorder have first-level symptoms, and it is not uncommon for other psychiatric diseases to have such symptoms. However, by the 1970s, the drawbacks of pure symptomatology diagnosis were discovered, and more complete diagnostic criteria were explored. However, K Sohneider’s diagnostic criteria remained a relatively strict criterion. Since the 1970s, a number of advances in psychiatric research have been made, one of which is the WHO International Pilot Study on Schizophrenia (IPSS). “Carpenter et al. (1976) used the PSE test to collect some of the data from the International Schizophrenia Collaborative, and identified nine common symptoms of schizophrenia and three common symptoms of non-schizophrenia by electronic computer statistics. The three most common symptoms of non-schizophrenia are early awakening, depressed expression, and elevated mood. He noted that at least four of these symptoms are required to diagnose schizophrenia. According to his data, 80% of acute and subacute schizophrenic disorders have more than 5 prevalent symptoms, suggesting that common diagnostic criteria can be used in countries and regions with very different backgrounds. The criteria currently in place in China have a different understanding of the concept of illness, resulting in inconsistencies in diagnosis and poor reproducibility, and due to clinical and scientific research needs, increasingly strict and perfect diagnostic criteria for clinical work have emerged in various countries and regions around the world. Such criteria should be easy to observe, easy to measure, and easy to unify views. For schizophrenia, only symptomatological criteria meet these conditions, and thus the Feighner diagnostic criteria (1972) and the Spitzer diagnostic criteria for research were developed in the United States. On this basis, in 1980, the American Psychiatric Association published the DSM-III, which established a symptom-based diagnosis of mental disorders. 1992 saw the publication of the International Classification of Diseases, 10th Revision (ICD-10) by WHO, which also established diagnostic criteria for mental disorders, although with the participation of American experts, there were still differences with the American criteria. Recently (1994), the DSM-IV was published in the United States, and these two major diagnostic classifications have had a large impact internationally. The diagnostic criteria for schizophrenia in China, in the symptom criteria, accept the concept of Brule’s basic symptoms and certain elements of pathological experience in the additional symptoms: e.g., psychotic automatism, primary delusions, including elements of Sohneider’s first-level symptoms, and Kreppelin’s taxonomic concept of disease, which is also reflected in our traditional diagnostic criteria, i.e., a tendency for the course of the disease to progress, leading to a In 1983, Xu Yuxin published the first version of the operational diagnostic criteria for schizophrenia in the epidemiological survey manual of 12 regions in China, and the content of the symptom criteria was very close to that of DSM-III. In 1984, the neuropsychiatric branch of the Chinese Medical Association was more stringent in the symptom criteria, requiring at least two typical characteristic symptoms or three atypical symptoms. In April 1989, the Chinese Classification of Mental Disorders and Diagnostic Criteria (CCMD-II), developed by the Chinese Society of Neuropsychiatry, was slightly modified in terms of severity, and in July 1993, after referring to the draft of ICD-10 and DSM-IV, the Neuropsychiatric Branch of the Chinese Medical Association summarized the revised opinions from all over China and formed the CCMD-2-R. The diagnostic criteria for schizophrenia in China have been fully aligned with the international diagnostic criteria, and the recently published CCMD-3 is basically similar to the diagnostic points of ICD-10, emphasizing the presence of at least two of the nine symptoms similar to ICD-10, which is slightly stricter than the diagnostic criteria for ICD-10 symptoms. However, the vast area of China, the regional differences, the different speed of information transmission, the different degrees of openness and closedness, as well as the different levels of psychiatric expertise, the differences in knowledge and understanding of its diagnosis, and even the fact that some physicians in specialized hospitals do not understand the diagnostic criteria of ICD-10, will definitely affect the promotion and use of CCMD-3. Therefore, it is necessary to take many measures such as holding various workshops to improve the level of use by physicians and reduce the mutual misdiagnosis rate of schizophrenia. Otherwise, misdiagnosis and mistreatment may occur, and even accidents may occur. Notes on the application of diagnostic criteria: ① Any diagnostic criteria for schizophrenia, such as those in the ICD-10, DSM-IV, and CCMD-3, are basically becoming more internationalized and standardized, and are terms and rules; ② Establish reasonable and appropriate criteria for the use of the ICD-10 in combination with the CCMD-3; ③ Not just grasping the criteria will improve the compliance rate of schizophrenia, but also requires study and (3) not only grasping the criteria will improve the compliance rate of schizophrenia, but also learning and accumulation of clinical experience; (4) it is necessary to analyze the cases longitudinally and horizontally and apply the criteria rationally in conjunction with the clinical reality, rather than just carrying out dead criteria and hard diagnosis; (5) special cases should be treated specially. The most commonly used diagnostic criteria are the CCMD-3 criteria, DSM-IV criteria and ICD-10 criteria, which are good guidance for clinicians, highly operational and reproducible, and undoubtedly helpful for doctors in clinical research work. The three different diagnostic criteria for schizophrenia are described below: ICD-10 diagnostic criteria for schizophrenia: Schizophrenia is generally characterized by basic and characteristic distortions of thought and perception, and inappropriate or retarded affect. Consciousness is usually clear and intelligence is intact, but some cognitive impairment may occur during the course of the illness. The disorder affects the most basic functions that allow normal people to maintain individuality, uniqueness and self-directed experience. The following is a list of symptoms that are of particular diagnostic significance and often occur together. (1) Thought chirping, thought insertion or thought withdrawal, and thought broadcasting. (2) Obviously involving body or limb movements, or specific thoughts, behaviors or sensations of being affected, controlled or passive delusions, or delusional perceptions. (3) Hallucinations that follow the patient’s behavior or discuss the patient with each other, or other types of hallucinations that originate from a part of the body. (4) Culturally inappropriate and impossible persistent changes of some other type, such as having a religious or political identity, or superhuman powers and abilities (e.g., the ability to control the weather or communicate with outsiders from another world). (5) Accompanied by fleeting or underdeveloped delusions with no apparent emotional content, or by persistent hypervalent ideas or any unrelated hallucinations that occur daily for weeks or days on end. (6) Disconnected thoughts or unrelated interjections, resulting in incoherent speech, or impertinent or newly composed words. (7) Catatonic behavior, such as excitement, posturing, or waxing flexion, defiance, reticence, and rigidity. (8) Negative symptoms, such as marked emotional indifference, paucity of speech, delayed or uncoordinated emotional response, often leading to social withdrawal and decreased social functioning, but it must be clarified that these symptoms are not due to depressive symptoms or antipsychotic treatment. (9) Significant and persistent changes in some aspects of personal behavior of a general nature, manifested by loss of interest, lack of purpose, laziness, self-focus, and social withdrawal. The diagnosis of schizophrenia usually requires the presence of at least one of (1) to (4) above (often two or more symptoms if less clear) within a period of 1 month or more. Or a well-defined symptom from at least two of the symptom clusters in (5) through (8), a condition that meets this symptom requirement but is less than 1 month old (with or without treatment) should be diagnosed first as an acute schizophrenia-like psychotic disorder (F23.2) and then reclassified as schizophrenia if the symptoms persist for a longer period of time. A review of the course of the illness reveals a distinct prodromal period weeks or months before the onset of psychotic symptoms, manifested by loss of interest in work, social activities, personal grooming, and hygiene, with widespread anxiety and mild depression or preoccupation. Since the time of onset is the only criterion for calculating the duration of the disease, the 1-month duration criterion applies only to the characteristic symptoms described above, but not to any prodromal non-psychotic phase. In the presence of major depressive or manic symptoms, schizophrenia should not be diagnosed unless it is clear that schizophrenic symptoms precede affective psychosis, and if schizophrenic symptoms occur concurrently with affective symptoms and are balanced, then schizoaffective disorder should be diagnosed even if the schizophrenic symptoms meet the diagnostic criteria for schizophrenia (F25.1). Schizophrenia should not be diagnosed in the presence of a definite brain disease or in the presence of drug intoxication or withdrawal. Similar disorders occurring in epilepsy or other brain disorders should be coded at F06.2, while those caused by drugs should be coded at F1x.5. DSM-IV diagnostic criteria (1) Two or more of the following characteristic symptoms for 1 month (or less than 1 month if effectively treated): (1) delusions; (2) hallucinations; (3) speech disorders (e.g., frequent verbal disorganization or incoherence); (4) significant behavioral disturbances or (5) negative symptoms such as emotional indifference, poor thinking or reduced volition. Note: If the symptoms have the following characteristics, only one of them also meets the criteria: bizarre delusions, hallucinations with continuous comments on the patient’s thoughts or behavior; two or more voices arguing with each other. (2) Socio-occupational deficits: one or more socio-occupational functions such as work, interpersonal relationships or self-care are significantly poorer than before the onset of the disease for a long period of time after the onset of the disease (if the onset of the disease is in childhood or adolescence, the patient is unable to reach the same age level of learning). (3) The duration of the disease and the signs of clinical disorder last for at least 6 months. At least 1 of these 6 months should meet the criteria of (1) (or less than 1 month with effective treatment) and may include prodromal or residual symptoms. During this period, clinical symptoms are predominantly negative, or two or more less typical (1)-type symptoms, such as bizarre thoughts, unusual sensory experiences, etc. (4) It is necessary to exclude schizoaffective disorder, and the key points to distinguish between mood disorder or schizoaffective disorder and mood disorder with psychotic symptoms are as follows: ① No depression, mania or mixed state coexisting with the symptoms in criterion (1). ②If the mood disorder occurs during the episode, its duration should be shorter than that of psychotic symptoms. ③It is necessary to exclude the paradoxical psychological state caused by substance abuse and common drugs, i.e., the psychiatric disorder is not due to the physical effects of substance abuse or common drugs on the body. (6) Relationship to pervasive developmental disorder. In the case of autism or other pervasive developmental disorders, the diagnosis of schizophrenia can be made again only if the hallucinatory delusions persist for more than 1 month. CCMD-3 diagnostic criteria (1) Symptom criteria: At least two of the following, not secondary to disorders of consciousness, mental retardation, or elevated or depressed affect, as otherwise specified for simple schizophrenia (1) recurrent verbal hallucinations; (2) obvious lax thinking, broken thinking, incoherent or poor thinking or poor thinking content; (3) thinking is inserted, withdrawn, broadcast, interrupted or forced thinking; (4) passive, controlled or insightful experience; (5) primary delusions (including delusional perception, delusional state of mind) or other absurd delusions; (6) logical inversion of thinking, pathological symbolic thinking or (7) emotional inversion or obvious emotional indifference; (8) nervousness syndrome, bizarre behavior or stupidity; (9) obvious hypoactive will or lack of will. (2) Severe criteria: self-awareness impairment, with severe impairment of social function or inability to carry out effective conversation. (3) Disease duration criteria: ①meet the symptom criteria and severity criteria has lasted at least 1 month, simple type is otherwise specified. (2) If the symptoms of schizophrenia and affective psychosis are met, when the affective symptoms are reduced to the extent that the symptoms of affective psychosis cannot be met, the schizophrenic symptoms must continue to meet the symptoms of schizophrenia for at least 2 weeks before the diagnosis of schizophrenia is made. (4) Exclusion criteria: exclude organic mental disorders and psychoactive substances and non-addictive substances caused by mental disorders. Patients with schizophrenia who are not in remission should be diagnosed concurrently if they have the two aforementioned disorders in this subparagraph. (1) Diagnostic criteria for simple schizophrenia: (1) predominantly negative symptoms such as paucity of thought, indifference to emotion, or reduced volition, and never obvious negative symptoms; (2) severely impaired social functioning, tending toward mental decline; (3) insidious onset and slow development, with a duration of at least 2 years, often starting in adolescence. (2) Diagnostic criteria for post-schizophrenic depression: (1) the diagnosis of schizophrenia within the last year, and depressive symptoms appear when the schizophrenic condition has improved but not cured. (2) At this time, depression lasting at least 2 weeks is the main symptom, and although psychotic symptoms remain, they are no longer the main clinical phase. (3) Exclude depression and schizoaffective psychosis. (3) Schizophrenia in remission: schizophrenia has been diagnosed, but now the clinical symptoms have disappeared and self-awareness and social functions have been restored for at least 2 months. (4) Residual schizophrenia: (1) The diagnosis of schizophrenia was met in the past and has not been in remission for at least 2 years. (2) The condition has improved, but at least one of the following remains: A. individual positive symptoms; B. individual negative symptoms; C. personality changes. ③Social function and self-awareness deficits were not severe. (4) Relatively stable in the last 1 year, no significant improvement or deterioration. (5) Chronic phase: ① consistent with the diagnosis of schizophrenia; ② the course of the disease lasts at least 2 years. (6) schizophrenic decline: ① meet the diagnostic criteria of schizophrenia; ② the last year is mainly mental decline, social function is severely impaired, and become mentally disabled. Application principles of diagnostic criteria: must be applied under the guidance of a psychiatric clinician with extensive experience in the specialty. ① After fully grasping the patient’s abnormal mental activity state, then analyze the criteria; ② The determination of negative symptoms should be strictly controlled; ③ Must exclude pseudo-symptoms; ④ Must meet all diagnostic criteria items, can not meet some; ⑤ Can not confirm the diagnosis of the case, should be longitudinal follow-up, pending later correction of the diagnosis.