The subtypes of schizophrenia

Tao Yuan xU

Department of Psychiatry,Huashan Hospital,Fudan University,Shanghai200040,China

The subtypes of schizophrenia

Tao Yuan xU

Department of Psychiatry,Huashan Hospital,Fudan University,Shanghai200040,China

This year（2011）is the centenary of the coining of the diagnostic label‘schizophrenia’.It is also a time in which revisions of both the ICD and DSM classification system s for mental illnesses are being actively debated.As part of this process one of the major proposed changes for DSM-5 is the com plete elimination of the sub-types of schizophrenia（http://www.dsm5.org ）.There is good reason to re-consider this proposed change.

Previously labeled as‘insanity’,‘dementia’,‘neuropathy’and so forth,schizophrenia has been recognized as one of the most common serious mental disorders since the beginning of the 20th century.Over100 years ago Kraepelin differentiated‘dementia praecox’from organic dementias and from affective disorders including under this rubric conditions previously labeled as paranoid dementia,catatonia and hebephrenia.Soon after that Bleuler,influenced by the theories of Freud,proposed the new term‘schizophrenia’which gradually rep laced the dementia praecox label and has persisted to the present day.Bleuler identified four subtypes（paranoid,catatonic,hebephrenic,and simp le）,a sub-classification that has also remained largely intact in international classification system s up to the present,though the hebephrenic label w as changed to‘disorganized’in 1980 version of the DSM.The third edition of the DSM eliminated the‘simple’subcategory but the ICD-10,the Chinese diagnostic system,the German diagnostic system and other diagnostic system s retain this subcategory.In Japan concern about the stigma associated with the‘schizophrenia’label led to a re-labeling of the condition in Japan as‘Sensory Integration Syndrome’,but the four subcategory labels have been retained.

In the first half of the 20th century these subcategories w ere used to predict prognosis and to select treatment modalities（at the time the only specific treatments available were electroconvulsive therapy［ECT］and insulin therapy）.For example, paranoid type schizophrenia was less likely to develop into a disabling dementia and insulin therapy was considered most effective；catatonia responded w ell to ECT；and the prognosis of disorganized and simple schizophrenia was poor.But with the widespread introduction of antipsychotic medications in the second half of the 20th century the prognosis for schizophrenia changed dramatically.Despite lacking a definitive cure,many schizophrenic symptom s w ere controlled so it was difficult to clearly sub-classify patients into one of the original four subtypes.

Data on the subtypes of patients with schizophrenia discharged from the Shanghai Mental Health Center—probably the largest mental health institution in China—for 1958-1959 and for 2001-2010 highlight this change（Table 1）.In these relatively large samples of discharged patients,the proportion diagnosed as one of the original four subtypes of schizophrenia（assessed using criteria that are essentially identical to ICD criteria）has dropped dramatically over this 50-year period,from 46.3%to 5.5%.With the exception of paranoid type,the other three original types（catatonic,disorganized,and simple）are now so uncommon that they can probably be eliminated from the formal diagnostic system.

The International Pilot Study of Schizophrenia（IPSS）organized by the WHO in the 1970s reported differences in the prevalence of different subtypes of schizophrenia between developed and developing countries.But Iexpect that the distribution of subtypes in Shanghai over the last decade shown in Table 1 has come much closer to the distribution of schizophrenic subtypes seen in developed countries.Catatonic schizophrenia is relatively easy to diagnose but even in the 1950s in Shanghai—before the widespread use of antipsychotic medication—it was relatively uncommon.Subsequent studies reported that antipsychotics were much less effective than ECT in the treatment of catatonic schizophrenia.Sim ple schizophrenia is typically described as a condition with early onset of flat affect,lack of interest and introversion.In the latter part of the 20th century some of these young individuals may have been diagnosed as autism and others who are immersed in the virtual worlds provided by computers may be missed.

I think it’s important that in discussing diagnostic subtypes w e reconsider traditional concepts（some of which originated prior to the 20th century）including the meaning of a‘disease entity’.My recommendation is to dichotomize schizophreniainto two subtypes.Over the years experts have proposed different methods and labels for dividing schizophrenia into two basic types:‘genuine schizophrenia’versus‘schizophreniform schizophrenia’；‘Type I’versus‘Type II’（positive sym ptom type vs.negative symptom type）；‘paranoid’versus‘non-paranoid’；and so forth.Looking at our data from Shanghai it appears that the most reasonable division would be between a‘typical’schizophrenia subtype（previously labeled as‘process schizophrenia’or‘true schizophrenia’）and an‘atypical’schizophrenia subtype（previously labeled as‘reactive schizophrenia’or‘schizophreniform schizophrenia’）.

Table 1.Schizophrenic subtypes of discharged patients from the Shanghai Mental Health Center in two different time periods

1. xu TY.Clinical and follow-up data of 2000 schizophrenic patients.Chinese J Berv Mental Dis,1979,5（5）:244-247.（in Chinese）