Schizophrenia (Schizophrenia) is the most common disease characterized by basic personality change, division of thinking, emotion and behavior, and disharmony of mental activities and environment. This disease has been discussed for a long time. Since the middle of the 19th century, European psychiatry has regarded different symptoms of this disease as independent diseases. The first person who proposed the concept of "schizophrenia" was Swiss psychiatrist E. Bleuler (1911) in the 20th century. The etiology of the disease is still unknown. The role of genetic factors and environmental factors in the occurrence of the disease is supported by more scientific data. Biochemical metabolism research is still in the hypothesis stage.
The research results in the past hundred years only found some possible pathogenic factors.
Possible pathogenic factors of schizophrenia
Biological factors
1. Genetic factors are the most likely quality factors of schizophrenia. Domestic pedigree survey data show that the prevalence rate of relatives of schizophrenics is 6.2 times higher than that of ordinary residents. The closer the blood relationship is, the higher the prevalence rate is. The study on twins shows that monozygotic twins with almost the same genetic information have a much higher incidence of the same disease than those with not the same genetic information. Based on 11 research data in recent years, the incidence of monozygotic twins with the same disease (56.7%) is 4.5 times higher than that of twins with the same disease (12.7%), and 35-60 times higher than that of the general population. It shows that genetic factors play an important role in the occurrence of this disease. The study of foster children also proves that genetic factors are the main factors of this disease, while environmental factors are less important. Previous studies have proved that diseases are not inherited by type. At present, it is believed that polygenic inheritance is the most likely, and some people believe that it is autosomal single gene inheritance or polygenetic inheritance. Shields found that the milder the disease, the more complicated the etiology, and the more polygenetic. The combination of prospective research on high risk families and molecular genetic research may clarify some problems. It has been reported in China that the human proto oncogene Ha-ras-1 was used as a probe to analyze the restriction fragment length polymorphism of the genome of patients with psychosis. The results suggest that there may be a DNA sequence related to schizophrenia and bipolar affective psychosis on chromosome 11.
2. Personality characteristics: About 40% of the patients have the characteristics of unsociable, cold, sensitive, suspicious, imaginative, etc., namely introverted personality.
3. Others: The onset of schizophrenia has a certain relationship with age, most of which occur in young adults, and about 1/2 of the patients are 20-30 years old. The age of onset is related to the clinical type. The onset of paranoid type is late. Some data suggest that the average age of onset of paranoid type is 35 years old, and that of other types is 23 years old.
In the 1980s, the overall prevalence rate of women (7.07%) and the time point prevalence rate (5.91%) were significantly higher than those of men (4.33%, 3.68%).
When describing the relationship between personality and schizophrenia, Kretschmer pointed out that 61% of patients were slim and athletic, 12.8% were obese, and 11.3% were obese Dysplasia Type.
Schizophrenia is a very common phenomenon after physical diseases or childbirth, which may be the non-specific effect of psychological and physiological stress. Some patients Brain trauma Post infectious disease; Viral substances have been reported in cerebrospinal fluid of schizophrenic patients; Physical factors such as aggravation during menstruation may be the inducing factors, but its value in the pathogenesis of schizophrenia needs to be further confirmed.
Psychosocial factors
1. Environmental factors ① The parents' personality, words and deeds, behavior, and education methods (such as indulgence, indulgence, and strictness) in the family will affect the children's physical and mental health or lead to personality deviation. ② The relationship between family members and the disorder of their mental communication. ③ Unstable life, crowded living, unstable occupation, poor interpersonal relationship, noise interference, environmental pollution, etc. all play a role in the pathogenesis. The incidence of schizophrenia in rural areas was significantly lower than that in urban areas.
2. Psychological factors generally believe that life events can induce schizophrenia. Such as dropout, lovelorn, study stress, family disputes, marital discord, and mental accidents all have a certain impact on the onset of disease, but these events are not special in nature. Therefore, psychological factors are only inducing factors.
Pathogenesis of schizophrenia
Biochemical metabolic disorder
Long ago, people suspected that psychosis was caused by toxic substances, and extensive research has been carried out. With the development of psychopharmacology, great progress has been made in the study of biochemical pathogenesis of schizophrenia. The following hypotheses are more significant.
1. The dopamine hypothesis In recent years, research has found that amphetamine can promote the release of dopamine into the synaptic space, and can also make normal people produce a kind of clinical manifestations of schizophrenia; Various antipsychotic drugs can antagonize the dopamine sensitive cyclic adenylase and block the postsynaptic dopamine receptor, which is consistent with their clinical potency; The density of dopamine receptors increased in the caudate nucleus, putamen nucleus and nucleus accumbens of schizophrenia; It is suggested that the occurrence of schizophrenia is related to excessive dopa receptor activity in some parts of the brain. However, the direct evidence of this hypothesis is still insufficient, and there are still shortcomings. Some patients have poor drug efficacy, so we can not use the Dopa hypothesis to explain it.
2. Methyl transfer hypothesis: the quasi psychotic drug cactus alkaloid is the 3-methylated product of catecholamine, and the dimethyltryptamine is the N-methyl derivative of tryptamine, which can cause schizophrenia like symptoms in healthy subjects. It is speculated that the occurrence of schizophrenia may be related to the excessive methylation of dopamine or serotonin and other neurotransmitters, resulting in the accumulation of toxic products of methylation in the body.
3. In recent years, it has been found that the activity of monoamine oxidase (MAO) in platelets of patients with chronic schizophrenia is reduced, and the activity of monoamine oxidase in platelets of the proband and his uninfected monozygotic twins is reduced. It is believed that the change of enzyme activity is a sign of individual genetic vulnerability. Those who proposed the hypothesis of 5-hydroxytryptamine (5-HT) transmission disorder found that the content of 5-HIAA in the brain fluid of schizophrenic patients was low, and the synthesis and degradation of 5-HT in the blood were reduced, suggesting that the disease might be related to the decrease of 5-HT activity in the brain of patients. Some people think that the occurrence of schizophrenia may be related to the imbalance between the dopamine system (too active) and the 5-HT system (too inactive) in the brain.
Physiological hypothesis of advanced neuroactivity
Pavlov school believes that the symptoms of schizophrenia are generated on the basis of the chronic hypnotic state of the cerebral cortex. The inhibition process of different parts, ranges and degrees can lead to different mental symptoms. When the inhibition process affects the subcortical emotional reflex arc, there will be emotional indifference and dullness. It also uses pathological excitatory foci and negative induction of cerebral cortex to believe in delusions without doubt and lack of criticism.
Immunological hypothesis
It is believed that schizophrenia is an immune reaction produced by some abnormal antigen. Heath, based on his research findings, proposed that schizophrenia was caused by damage to special parts of the brain caused by antibodies, but Heath's findings have not been confirmed by other studies. Other studies found that there was no antibody in the patient's serum and brain fluid, and the content of immunoglobulin in abnormal lymphocytes was abnormal, suggesting that schizophrenia was the result of abnormal immune response. However, the specificity of these changes is still uncertain.
Pathogenesis of psychology
According to the theory of psychodynamics, schizophrenia is characterized by the withdrawal of Libido to the point of attachment to the self, which makes the outside world meaningless and will not produce empathy M. Klein believes that the source of schizophrenia is in early childhood, during which the self and the mother's avatar are often split into two parts: "completely good and completely bad". If you cannot successfully pass through this period, you may suffer from schizophrenia later. The psychophysiological hypothesis believes that there are specific defects in the perception and cognition of schizophrenic patients except for the quality stress effect. A considerable number of patients are "overarousal", especially those who are slow to retreat STD In the example, this kind of performance is more. Kraepelin and Bleuler both believe that most schizophrenia symptoms can be traced back to the weakening of attention and perception.
Theory of functional imbalance between cerebral hemispheres
It is a new etiological theory based on the development of neuropsychology in the past 20 years. Its contents are as follows: ① The thinking disorder of schizophrenia is the result of the dysfunction of the left hemisphere. ② It is caused by the weakening of the right hemisphere function and the hyperactivity of the left hemisphere function. ③ The functional defect of the corpus callosum causes the obstruction of information traffic in the left and right hemispheres, or due to its hyperfunction, too much information is transmitted, resulting in excessive activity in the left hemisphere. ④ Schizophrenia can be divided into two types: left hemisphere over dominance syndrome equivalent to delusional performance and left hemisphere hypofunction syndrome equivalent to non delusional performance.
reference resources
What are the causes of schizophrenia Family doctors Online January 14, 2014
What is the main cause of schizophrenia? Dayang. com December 14, 2012
