OBJECTIVE: To explore the standardized method of differential diagnosis of depressive neurosis and to improve the accuracy. METHODS: A total of seven aspects of essential combination of symptoms, etiology, intrinsic relationship, severity, duration, exclusion of symptoms and non-organic pathological basis were used as elements of the differential diagnostic model of depressive neurosis, which was clinically validated using the dual dialectical treatment of neurosis. RESULTS: Depressive neurosis has significant differences compared to other disorders with depressive neurosis-like syndromes. The necessary combination of symptoms, etiology and intrinsic relationships is central to the differential diagnosis; the exclusion of symptoms, the basis of non-organic pathology, is also important, but whether it becomes the basis of differential diagnosis in some specific cases depends on the situation; the severity and duration of the disease have some significance. CONCLUSION: The differential diagnostic model of depressive neurosis has the advantage of being more meticulous and standardized and accurate. The diagnosis of depressive neurosis has been gradually withdrawn from the medical field in recent years, and the name of neurosis has been taken from the American Diagnostic Criteria for Diseases DSM-III-R. since 1987, so the diagnosis of depressive neurosis does not exist naturally. The International Diagnostic Criteria for Diseases ICD-10, which changed the name of neurosis to neurotic disorder, simply discarded depressive neurosis. It is still a subtype of neurosis in the Chinese Classification and Diagnostic Criteria of Mental Disorders CCMD-2-R, and is no longer retained in the Chinese Classification and Diagnostic Criteria of Mental Disorders CCMD-3. Clinically, physicians now commonly use names such as depression, depressive disorder, depressive episode, and poor mood to replace the diagnosis of depressive neurosis. In fact, this is the result of a lack of essential understanding of depressive neurosis. The diagnosis and differential diagnosis of depressive neurosis can be fundamentally clarified and organized; however, it requires new theory and practice. The differential diagnosis model of depressive neurosis is described based on the theory and practice of dual dialectical treatment of neurological disorders, combined with the relevant contents of the Chinese Classification and Diagnostic Standard of Mental Disorders CCMD-2-R [1]. It is also among the differential diagnosis model system of neurosis. 2 , differential diagnostic model 2.1 Essential combination of symptom aspects 2.1.1 Essential combination of symptom basis. The main symptoms of depressive neurosis (clinical phase) can be broken down into two parts, the first part can be called the common or core symptom part of neurosis, manifested as excessive thinking or with excessive attention; the second part can be called the personality part or subtype characteristic part, manifested as the symptoms of depressive neurosis usually considered; one without the other. Expressed mathematically: the necessary combination of symptoms of depressive neurosis = common core symptoms of neurosis + symptoms of depressive neurosis. The symptoms of depressive neurosis, as expressed by CCMD-2-R, are “persistent mild to moderate depression as the main clinical phase, accompanied by at least three of the following symptoms: 1) loss of interest, but not loss of interest; 2) pessimism and disappointment about the future, but not despair; 3) self-consciousness of fatigue or weakness; 4) decreased self-evaluation, but willing to accept encouragement and praise; 5) Reluctant to actively interact with people, but passive contact good, willing to accept sympathy and support; 6, have the idea of dying, but heavy concern; 7, self-conscious of serious illness difficult to treat, but actively seek treatment, hope to be cured.” 2.1.2 Differential diagnosis by the necessary combination of symptom basis For depressive neurosis, common core symptoms + depressive neurosis symptoms, indispensable, otherwise, it cannot be diagnosed as depressive neurosis. Patients lacking the first part of symptoms as the core basis cannot be called depressive neurosis; their depressive neurosis-like symptoms can only be called depressive neurosis-like syndrome associated with a certain disease, which can exist in many diseases such as: post-concussion syndrome, cerebral arteriosclerosis, hypothyroidism, menopausal syndrome, somatic forms of autonomic dysfunction, somatization disorders, psychoactive substance-induced psychotic disorders, depression, schizophrenia, etc. As for patients who lack the second part of symptoms, since they do not have depressive neurosis-like symptoms, they naturally cannot be diagnosed as depressive neurosis. 2.2 Etiological aspects 2.2.1 Etiological basis. The persistent evil thoughts are marked by persistent evil thoughts, and the persistent evil thoughts are formed gradually before the symptoms of depressive neurosis, and then coexist until the present. Persistent obsessions are centered on excessive thinking or excessive attention, intertwined with six factors: thinking, emotion, attention, memory, will, and personality. 2.2.2 Differential diagnosis on the basis of etiology For patients with complex conditions, it seems from the surface to have the first part of the symptoms of depressive neurosis and the second part of the symptoms, but if excessive thinking or with excessive attention does not form the etiology persistent evil thoughts, then it is also not diagnosed as depressive neurosis, and other diagnoses should be made. Example analysis. In hypothyroid patients, a combination of symptoms similar to depressive neurosis occurs when there is a certain amount of secondary hypochondriasis or hyperacusis: depressive neurosis-like syndrome (as well as somatic symptoms of hypothyroidism, etc.) + hypochondriasis or hyperacusis. In this case, it is difficult to tell the difference between the two disorders by the appearance of the symptom combination alone, but the etiology of depressive neurosis is immediately apparent. In depressive neurosis, hypochondriasis or hyperconcentration first forms the etiology of persistent evil thoughts before triggering depressive neurosis symptoms; in hypothyroidism, a certain amount of hypochondriasis or hyperconcentration appears or dies with depressive neurosis-like syndromes (as well as somatic symptoms such as hypothyroidism) and is not etiologic in nature. 2.3 Intrinsic relationship aspects 2.3.1 Intrinsic relationship basis There is an inevitable link between the persistent evil thoughts of depressive neurosis (etiology) and the clinical phases (symptoms). Among the general relationships, the most easily perceived one is the positive proportional extinction relationship triggered by the etiology. It is expressed that the scale of the cause determines the scale of the disease mechanism and symptoms; the more complex and extensive the cause, the more intense the disease mechanism initiated, and the more symptoms produced, and vice versa. 2.3.2 Differential diagnosis on the basis of intrinsic relationship Some mental illnesses have certain psychological causes, and the manifestations of the illness are also or similar to depressive neurosis, but if there is no “inevitable connection between persistent evil thoughts (etiology) and clinical phases (symptoms) ——- a positive relationship between etiology and growth”, then it cannot be diagnosed as depressive neurosis. Depressive neurosis cannot be diagnosed. Example analysis. Many psychogenic disorders, some schizophrenia, dysthymia, depression, etc., often have or coincide with a history of mental stimulation in the earliest period of the disease, and are considered to have a certain “psychogenic” cause. Some of them also have certain symptoms of depressive neurosis. However, a careful study will reveal that these patients do not have “an inevitable connection between the persistent evil thoughts (etiology) and the clinical phase (symptoms), and a positive relationship between the etiology and the growth”, so they cannot be diagnosed as depressive neurosis. However, a very small number of acute psychogenic disorders with mild symptoms admit that “there is an inevitable connection between persistent evil thoughts (etiology) and clinical phases (symptoms), and a positive proportional relationship between the etiology triggered by the etiology and the duration”, so after the acute reaction period, the diagnosis of depressive neurosis can be modified if the conditions of depressive neurosis are reached. 2.4 Course of illness 2.4.1 Course of illness According to the diagnostic criteria of CCMD-2-R depressive neurosis, the duration of illness is “at least two years, with depressed mood for most of the entire course of the illness. If there are normal intervals, they should not exceed a maximum of two months at a time”. The disease is defined by its nature, the duration is only cosmetic. If the differential diagnosis model shown in this paper is used, the duration of the disease is actually very short, 6 months, because it can be determined from the essence. 2.4.2 Differential diagnosis based on the duration of illness If only the duration of illness is not enough, the diagnosis of depressive neurotic reaction can be tentatively made and the diagnosis can be revised at a later time. However, as the level of differential diagnosis improves, the criteria for the duration of illness will be greatly reduced in the future. 2.5 Severity 2.5.1 Severity based on impaired social functioning or inescapable mental distress that prompts the person to seek medical attention. 2.5.2 Severity-based differential diagnosis. If the person does not reach the severity level, the diagnosis of depressive neurosis is not made for the time being. 2.6 Exclusion of symptoms 2.6.1 Basis for exclusion of symptoms In addition to the first part of symptoms and the second part of symptoms mentioned above, patients with depressive neurosis should not persistently have the following symptoms: dysthymic dissociative symptoms or conversion symptoms, manic symptoms, heavy depressive symptoms (e.g., marked psychomotor depression, morning heavy and evening light symptoms, . severe guilt or self-guilt, more than one suicide attempt), psychotic symptoms, deficits in self-awareness, impaired reality testing ability, etc. What is the rationale? On the one hand, such symptoms are beyond the scope of mild mental disorders such as depressive neurosis. On the other hand, if such symptoms are present, one of the following “etiological basis” and “intrinsic relationship basis” must not be valid and can be distinguished. In case of transient disorder, it can be analyzed with reference to the absence of organic pathology. 2.6.2 Differential diagnosis based on exclusion of symptoms If the patient has persistent “exclusion of symptoms”, it means that his condition is beyond the scope of depressive neurosis and other mild mental disorders, and the pattern of performance is also qualitatively different from neurosis, so he cannot be diagnosed as depressive neurosis, and other diagnoses should be made. 2.7.1 No organic lesion as the basis Depressive neurosis has no organic lesion as the basis; or rather, depressive neurosis is not due to organic lesion. Various neurotic symptoms or their combination can be seen in infectious, toxic, visceral, endocrine or metabolic and organic brain diseases, called neurotic-like syndrome; similarly, if it is embodied as depressive neurotic-like symptoms, it is called depressive neurotic-like syndrome and cannot be called depressive neurosis. 2.7.2 Differential diagnosis based on the absence of organic lesions Generally speaking, it is relatively easy to make the diagnosis of depressive neurosis in the absence of organic lesions. However, when depressive neurosis-like symptoms are found after an organic lesion, how to determine whether the depressive neurosis-like syndrome is directly caused by the organic lesion or whether the organic lesion itself does not cause the depressive neurosis-like syndrome but rather the depressive neurosis is caused by excessive thinking or excessive attention? The clinical situation is often intricate and requires analysis to understand. The absence of organic lesions as the basis for depressive neurosis only means that depressive neurosis is not a direct result of organic lesions; however, it does not mean that patients with depressive neurosis no longer have organic lesions, nor does it mean that patients who have had organic lesions no longer suffer from depressive neurosis. As the body grows, ages, and undergoes certain factors, various organic lesions tend to increase with each passing day. The emergence or cure of organic lesions does not mean that depressive neurosis must automatically die out, so the differential diagnosis of depressive neurosis should be carefully analyzed. In some patients, after the appearance or cure of organic lesions, many new psychiatric problems arise, and the original symptoms of depressive neurosis can no longer be distinguished based on the internal relationship between the causes of depressive neurosis, it is not appropriate (or temporarily inappropriate) to make a diagnosis of depressive neurosis, but can be diagnosed as “a certain disease with depressive neurosis-like syndrome or a certain disease with mental disorder “. On the contrary, in some patients, after the appearance or cure of organic lesions, the basis of the internal relationship between the original symptoms etiology of depressive neurosis is still clearly identifiable, and there is no direct relationship between organic lesions and depressive neurosis-like symptoms, it is appropriate to keep the diagnosis of depressive neurosis at this time. The overall trick is that depressive neurosis must be judged by the three aspects of “symptom-etiology and intrinsic system”: if both exist, depressive neurosis still exists; if one is abolished, depressive neurosis is abolished. According to the relevant contents of CCMD-2-R, the exclusion criteria of depressive neurosis should firstly follow the exclusion criteria of neurosis: “The following disorders must be excluded to confirm the diagnosis: organic mental disorder, psychoactive and non-dependent substance-induced mental disorder, schizophrenia, paranoid psychosis, various psychotic disorders and affective disorders. Psychotic disorders”, followed by a further requirement of their own “absence of any of the following symptoms: 1, marked psychomotor depression; 2, early awakening and morning and evening symptoms; 3, severe guilt or self-guilt; 4, persistent loss of appetite and significant weight loss (not due to physical illness); 5, more than one attempted suicide; 6, inability to care for oneself; 6, inability to take care of oneself 6. inability to care for oneself; 7. hallucinations or delusions; 8. lack of self-knowledge”. Although this is the authoritative “exclusion criteria”, it is only partially justified. The following is a review of the theory of dual dialectical treatment of neurological disorders. In terms of “exclusion of organic psychiatric disorders”: ① Hypothyroidism patients with symptoms of depressive neurosis are generally no longer diagnosed as depressive neurosis in parallel. This is because these patients do not have the above-mentioned “necessary combination of symptoms, etiology, and internal relationship” and often have “heavy depressive symptoms, psychotic symptoms, impaired self-awareness, and impaired reality testing ability”, which are based on clear organic pathology. It is a disease based on a clear organic pathology. The neurological dichotomy is not effective for the depressive neurotic symptoms, but the treatment of hypothyroidism can control or eliminate the depressive neurotic symptoms. (2) In hypertension and coronary artery disease, if depressive neurotic-like symptoms are present, the diagnostic situation should be treated differently. In these patients, if the above mentioned “necessary combination of symptoms, etiology, and internal relationship” is present, the diagnosis of depressive neurosis can be juxtaposed, and in this case, the use of neurological dual dialectical treatment is good for the presence of depressive neurosis symptoms. In such patients, if the above-mentioned “necessary combination of symptoms, etiology, and internal relationship” is not present, only “hypertension, coronary heart disease, etc.” with depressive neurosis-like syndrome can be diagnosed, and depressive neurosis cannot be diagnosed concurrently. In this case, the use of neurological syndrome treatment is not useful for the presence of depressive neurosis-like symptoms. In the case of “psychoactive substances and non-addictive substances-induced mental disorders”: withdrawal reactions to euphoric drug overdose, hypnotic and sedative drugs, anxiolytic drugs, etc., if symptoms of depressive neurosis are present, the diagnosis should be treated differently. Generally speaking, if the withdrawal reaction period has passed and the symptoms of depressive neurosis have disappeared automatically, the diagnosis is no longer made; if the withdrawal reaction period has passed and the symptoms of depressive neurosis still exist, then depressive neurosis may exist, but further analysis is needed, and the above-mentioned “necessary combination of symptoms, etiology, and internal relationship” becomes the criterion for differential diagnosis. The above-mentioned “essential combination of symptoms, etiology, and intrinsic relationship” becomes the criterion for differential diagnosis. The reasons for this analysis are described above. “In the case of schizophrenia, paranoid psychosis, various psychotic disorders and affective disorders, the presence of symptoms of depressive neurosis is generally no longer a concurrent diagnosis of depressive neurosis. See above for the specific reasons for analysis. The “absence of any of the following symptoms” aspect. Depressive neurosis can have “early awakening, persistent loss of appetite and significant weight loss (not due to physical illness), . . inability to care for oneself,” but not “marked psychomotor depression, morning and evening symptoms, severe guilt or self-crime, . More than one suicide attempt, hallucinations or delusions, and deficits in self-awareness. Anxiety disorders, obsessive-compulsive disorders, phobias, and hypochondriacs, if they coexist with depressive neurosis-like symptoms, can be diagnosed together as depressive neurosis because they are of the same level of illness. They are mixed neuroses. In this case, the use of dual dialectical treatment of neurosis has a good effect on their coexisting symptoms. 3.2 How to distinguish depressive neurosis from major depressive disorder In the past, depressive disorder referred to “major depressive disorder” and did not include “depressive neurosis”. However, because depressive neurosis and major depressive disorder have many similarities and antidepressants are widely used and effective for them, they are often considered to be the same disease in people’s understanding, so they are gradually used to be diagnosed as “depressive disorder” in general in clinical practice. If antidepressant medication is the main measure of treatment and clinical control of symptoms is the goal, then even if depressive neurosis is misdiagnosed as depression, there is no big problem. However, if dual diagnosis and treatment is the main measure, and the aim is to pursue the root cause of the disease, then a strict and effective differential diagnosis is required to enter the appropriate treatment plan. The main points are as follows. One depressive neurosis has all the requirements of the differential diagnostic model described above. This is not the case for major depressive disorder or even for those whose manifestations are not yet severe. It is not based on the combination of symptoms, etiology and intrinsic relationships that meet the above requirements. In some cases, due to other discomforts, a combination of symptoms similar to depressive neurosis may occur when there is a certain hypochondriasis or hyperconcentration: symptoms of (heavy) depression + hypochondriasis or hyperconcentration. However, a certain amount of hypochondriasis or hyperconcentration appears or dies with the symptoms of (major) depressive disorder and does not have an etiological nature or a positive etiological relationship. In addition, some patients have a sense of emptiness or very slow thinking without any secondary hypochondriasis or hyperconcentration. The second is the identification of surface symptoms. Depressive neurosis does not have “marked psychomotor depression, morning and evening heavy symptoms, severe guilt or self-crime, . More than one suicide attempt”, while major depressive disorder may often have them. 3.3 Rethinking the treatment of survival Genuine depressive neurosis exists and will not disappear because people abandon the diagnosis; what it needs is accurate diagnosis and efficient treatment or even a cure. The American standard DSM-III-R has abolished the diagnosis of neurosis, and naturally there is no diagnosis of depressive neurosis; the international standard ICD-10 has abolished the diagnosis of depressive neurosis, and the Chinese standard CCMD-3 has also abolished the diagnosis of depressive neurosis. At present, depressive neurosis is often diagnosed clinically as depression, depressive disorder, depressive episode and bad mood, which is related to the effect of antidepressant and anti-anxiety drugs on it. However, the diagnosis should ultimately reflect the nature and characteristics of the disease. The efficacy of medications can only be used as a reference for diagnosis, not to mention that there are many therapies and medications that have some effect on depressive neurosis, and the current antidepressant and anti-anxiety medications are only effective but far from a cure for depressive neurosis. It is a very impetuous and risky behavior not to explore the essence of depressive neurosis, but to follow the trend of drug response and artificially overwhelm the diagnosis of depressive neurosis, or to easily change and apply the disease name and artificially overwhelm the diagnosis of depressive neurosis. The rational diagnosis model [8] and differential diagnosis model of depressive neurosis under the guidance of the dual diagnosis and treatment system of neurological disorders incorporates deeper contents such as symptom analysis, etiology determination and inner relationship corroboration, and the synergy between Chinese and Western medicine, so the diagnosis and differential diagnosis of depressive neurosis are clearer, which is extremely helpful for treatment plan selection and treatment prognosis. Therefore, I hope that in the future, we can work together with our colleagues to promote the academic development of depressive neurosis.