10 If the NSC 683864 diagnosis covers a broad spectrum of patients who might not share the same symptoms, then the search for one etiology and pathogenesis that could predict treatment response and outcome may be futile, Therefore, schizophrenia researchers have attempted to reduce the complexity
of schizophrenia by defining subtypes or dividing schizophrenia into one or more entities. Emil Kraepelin Volasertib purchase subdivided dementia praecox into subtypes based on the presence of one or more symptoms. His last attempt at subdividing Inhibitors,research,lifescience,medical dementia praecox/schizophrenia produced 10 different “clinical forms.” The Diagnostic and Statistical Manual of Mental Disorders (DSM) has followed his tradition and the current version (DSM-IV) recognizes three of his subtypes (paranoid type, disorganized [ie, hebephrenic] type, and catatonic type) and supplements them with Inhibitors,research,lifescience,medical two new ones (undifferentiated type and residual type). The Kraepelinian
subtypes are defined by the presence, severity, and duration of symptoms, but their validity has been questioned.11 For example, all subtypes, except the paranoid type, show poor temporal stability and might not represent a trait characteristic12-15 Bleuler acknowledged Inhibitors,research,lifescience,medical the heterogeneity of the schizophrenia construct without providing a solution to this puzzle16: I call dementia praecox “schizophrenia” … I use the word in the singular although it is apparent that the group includes several diseases … so far we have been unable to discover any Inhibitors,research,lifescience,medical natural lines of division within the described clinical
picture … the subdivision of the group of schizophrenias is a task for the future. A different approach to the complexity of schizophrenia can be traced back to the writings of John Russell Reynolds (1828-1896) and John Hughlings Jackson (1835-1911).17 Jackson proposed a model of abnormal brain function in neurological Inhibitors,research,lifescience,medical and psychiatric disorders based on the Cilengitide evolutionary theory that the brain had developed to increasingly more complex levels. He suggested that higher levels of brain function (eg, cortex) control the function of lower levels (eg, subcortical structures, brain stem). Negative symptoms arise from the paralysis of a given hypothetical level of brain function. Positive symptoms arise when higher levels of brain function are impaired and, due to a lack of inhibition, lower levels become apparent, creating “symptoms” normally not observed. In Jackson’s view, “where there is a positive symptom, a negative symptom must be.”17 The positive/negative dichotomy resonated in the community of schizophrenia researchers.