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Are Latent Thought Disorders the Core of Negative Schizophrenia?

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Phenomenology, Language & Schizophrenia

Abstract

Since its inception as a diagnostic entity, attempts have been made to divide schizophrenia into homogeneous subgroups. Kraepelin (1899) already distinguished more florid symptoms from those that were marked by losses or deficits; the latter were responsible for the term “dementia praecox”. Bleuler (1911) is well known and influential in Anglo-American psychiatry and is often viewed as a forefather of the distinction between positive and negative schizophrenia. For example, Pfohl and Andreasen (1986), Crow (1982), and Sommers (1985) see present-day negative symptoms as a reduced version of Bleuler’s fundamental or basic symptoms (disturbances of association and affect, ambivalence, and autism).

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References

  • Abels D: Der Konzentrations-Verlaufs-Test K-V-T (the course-of-concentration-test, 2nd ed). Berlin, Springer, 1961

    Google Scholar 

  • Allen HA: Dichotic monitoring and focussed versus divided attention in schizophrenia. British Journal of Clinical Psychology 21: 205–212, 1982

    Article  PubMed  CAS  Google Scholar 

  • American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, third edition, revised (DSM-III-R). Washington, DC: American Psychiatric Association, 1987

    Google Scholar 

  • Anath J, Chadirian A: Drug induced mood disorder. International Pharmacopsychiatry 15: 58–73, 1980

    Google Scholar 

  • Andreasen NC: Negative symptoms in schizophrenia: definition and reliability. Archives of General Psychiatry 39: 784–788, 1982

    PubMed  CAS  Google Scholar 

  • Andreasen NC: Positive vs. negative schizophrenia: a critical evaluation. Schizophrenia Bulletin 11: 380–389, 1985

    PubMed  CAS  Google Scholar 

  • Andreasen NC Akiskal HS: The specificity of Bleulerian and Schneiderian symptoms: a critical re-evaluation. Psychiatric Clinics of North America 6: 41–54, 1983

    PubMed  CAS  Google Scholar 

  • Andreasen NC, Flaum M: Schizophrenia: the characteristic symptoms. Schizophrenia Bulletin 17: 27–49, 1991

    PubMed  CAS  Google Scholar 

  • Andreasen NC, Flaum M, Swayze VW, Tyrrell G, Arndt S: Positive and negative symptoms in schizophrenia. Archives of General Psychiatry 47: 615–621, 1990

    PubMed  CAS  Google Scholar 

  • Andreasen NC, Olsen SA: Negative vs. positive schizophrenia: definition and validation. Archives of General Psychiatry 39: 789–794, 1982

    PubMed  CAS  Google Scholar 

  • Andreasen NC, Olsen SA, Dennert JW, Smith JW: Ventricular enlargement in schizophrenia: Relationship to positive and negative symptoms. American Journal of Psychiatry 139: 297–302, 1982

    PubMed  CAS  Google Scholar 

  • Ayd FJ: The depot fluphenazines: a reappraisal after 10 years’ clinical experience. American Journal of Psychiatry 132: 491–500, 1975

    PubMed  Google Scholar 

  • Arbeitsgemeinschaft für Methodik and Dokumentation in der Psychiatrie AMDP: Das AMDP-System: Manual zur Dokumentation psychiatrischer Befunde (The AMDP-System: Manual for the Assessment and Documentation of Psychopathology, 4th ed.). Berlin, Springer, 1981

    Google Scholar 

  • Asaranow RF, MacCrimmon DJ: Residual performance deficit in clinically remitted schizophrenics: a marker of schizophrenia? Journal of Abnormal Psychology 87: 597–608, 1978

    Article  Google Scholar 

  • Asaranow RF, MacCrimmon DJ: Span of apprehension deficits during postpsychotic stages of schizophrenia. Archives of General Psychiatry 38: 1006–1011, 1981

    Google Scholar 

  • Asaranow RF, MacCrimmon DJ: Attention/information processing, neuropsychological functioning, and thought disorder during the acute and partial recovery phases of schizophrenia: A longitudinal study. Psychiatry Research 7: 309–319, 1982

    Article  Google Scholar 

  • Beck AT: Depression Inventory. Philadelphia, Center for Cognitive Therapy, 1978

    Google Scholar 

  • Beck AT, Rush AJ, Shaw BF, Emery G: Kognitive Therapie der Depression. München, Urban & Schwarzenberg, 1981

    Google Scholar 

  • Bilder RM, Murkherjee S, Rieder, RO, Pandurangi, AK: Symptomatic and neuropsychological components of defect states. Schizophrenia Bulletin 11: 409–417, 1985

    PubMed  CAS  Google Scholar 

  • Bleuler E: Dementia praecox oder die Gruppe der Schizophrenien (Dementia Praecox or the Group of Schizophrenias). Leipzig, Deuticke, 1911

    Google Scholar 

  • Breier A, Wolkowitz OM, Doran AR, Roy A, Boronow J, Hommer D, Pickar D: Neuroleptic responsivity of negative and positive symptoms in schizophrenia. American Journal of Psychiatry 144: 1549–1555, 1987

    PubMed  CAS  Google Scholar 

  • Carpenter WT, Conley RR: Treatment approaches to negative symptoms. In JF Greden, R Tandon (eds): Negative Schizophrenic Symptoms: Pathophysiology and Clinical Implications (pp. 205–214). Washington, DC: American Psychiatric Press, Inc., 1991

    Google Scholar 

  • Carpenter WT, Heinrichs DW, Alphs LD: Treatment of negative symptoms. Schizophrenia Bulletin 11: 37–49, 1985

    Google Scholar 

  • Chaturvedi SK, Prasad Rao G., Mathai JP: Negative symptoms in schizophrenia and depression. Indian Journal of Psychiatry 27: 237–241, 1985

    PubMed  CAS  Google Scholar 

  • Ciompi L: Ist die chronische Schizophrenie ein Artefakt? Argumente und Gegenargumente (Is chronic schizophrenia an artefact? Arguments and counter-arguments). Fortschritte der Neurologie Psychiatrie 48: 237–248, 1980

    Article  CAS  Google Scholar 

  • Cornblatt BA, Lenzenweger MF, Dworkin, RH, Erlenmeyer-Kimling L: Positive and negative schizophrenic symptoms, attention, and information processing. Schizophrenia Bulletin 11: 397–407, 1985

    PubMed  CAS  Google Scholar 

  • Crow TJ: Molecular pathology of schizophrenia: more than one disease process? British Medical Journal 280: 1–9, 1980

    Article  Google Scholar 

  • Crow TJ: The biology of schizophrenia. Experientia 38: 1275–1282

    Google Scholar 

  • Crow TJ, Cross AJ, Johnstone ECD, Owen F: Two syndromes in schizophrenia and their pathogenesis. In: Henn FA, Nasrallah HA (eds.): Schizophrenia as a Brain Disease, pp. 196–234. New York, Oxford University Press, 1982

    Google Scholar 

  • Dixon WJ: BMDP Statistical Software. Berkley, University of California Press, 1985

    Google Scholar 

  • Endicott J, Spitzer RL: A diagnostic interview: the Schedule for Affective Disorders and Schizophrenia. Archives of General Psychiatry 35: 837–844, 1978

    PubMed  CAS  Google Scholar 

  • Goffmann E: Asylums. New York, Anchor Books, 1961

    Google Scholar 

  • Goetz KL, van Kammen DP: Computerized axial tomography scans and subtypes of schizophrenia: a review of the literature. Journal of Nervous and Mental Disease 174: 208–213

    Google Scholar 

  • Goldberg SC: Negative and deficit symptoms in schizophrenia do respond to neuroleptics. Schizophrenia Bulletin 11: 453–456, 1985

    PubMed  CAS  Google Scholar 

  • Green M, Walker E: Attentional performance in positive and negative schizophrenia. Journal of Nervous and Mental Disease 174: 208–213, 1986

    Article  PubMed  CAS  Google Scholar 

  • Green M, Walker E: Neuropsychological performance and positive and negative symptoms in schizophrenia. Journal of Abnormal Psychology 94: 368–377, 1985

    Article  Google Scholar 

  • Green M, Walker E: Susceptibility to backward masking in schizophrenics with positive and negative symptoms. American Journal of Psychiatry 141: 1273–1275, 1984

    PubMed  CAS  Google Scholar 

  • Gross G, Huber G, Klosterkötter J, Linz M: Bonner Skala für die Beurteilung von Basissymptomen BSABS (The Bonn Scale for the Assessment of Basic Symptoms). Berlin, Springer, 1987

    Google Scholar 

  • Gruhle HW: Die Psychologie der Dementia praecox (The psychology of dementia praecox). Zentralblatt für Neurologie 78: 454–471, 1922

    Google Scholar 

  • Gruhle HW: Psychologie der Schizophrenie (Psychology of Schizophrenia). In: Berze J, Gruhle HW (eds): Psychologie der Schizophrenie (Psychology of Schizophrenia), pp. 73–168. Berlin, Springer, 1929

    Google Scholar 

  • Hamilton M: A rating scale for depression. Journal of Neurology, Neurosurgery, and Psychiatry 23: 56–62, 1960

    Article  CAS  Google Scholar 

  • Harvey PD, Earle-Boyer EA, Levinson JC: Cognitive deficits and thought disorder: a retest study. Schizophrenia Bulletin 14: 57–65, 1988

    PubMed  CAS  Google Scholar 

  • Harvey PC, Serper MR: Linguistic and cognitive failures in schizophrenia. Journal of Nervous and Mental Disease 178: 487–493, 1990

    PubMed  CAS  Google Scholar 

  • Helwig J: Einführung in das SAS. transl. by G. Frenzel. Cary, North Carolina: SAS Institute Inc.

    Google Scholar 

  • Hemsley DR: Information processing and schizophrenia. In: Straube ER, Hahlweg K (eds): Schizophrenia. Concepts, Vulnerability, and Intervention, pp. 59–76. Springer, Berlin, 1990

    Google Scholar 

  • Hogarty GE, Muntzer MR: Pharmacogenic depression among schizophrenic outpatients: a failure to substantiate. Journal of Clinical Psychopharmacology 4: 17–24, 1984

    Article  PubMed  CAS  Google Scholar 

  • Huber G, Gross G, Schüttler R: Schizophrenie. Eine verlaufs-und sozialpsychiatrische Langzeitstudie (Schizophrenia. A long-term study of course and social psychiatric effects). Berlin, Springer, 1979

    Google Scholar 

  • Janzarik W: Dynamische Grundkonstellationen in endogenen Psychosen (Dynamic basic constellations of endogenous psychoses). Berlin, Springer, 1959

    Google Scholar 

  • Janzarik W: Schizophrene Verläufe. Eine strukturdynamische Interpretation (Schizophrenic courses. A structural-dynamic interpretation). Berlin, Springer, 1968

    Google Scholar 

  • Johnson DAW (1981). Studies of depressive symptoms in schizophrenia: I. The prevalence of depression and its possible causes. British Journal of Psychiatry 139: 89–93, 1981

    Article  PubMed  CAS  Google Scholar 

  • Johnson J: Depressive changes after fluphenazine treatment. British Medical Journal 3: 718, 1969

    Article  PubMed  CAS  Google Scholar 

  • Kane J, Honigfeld G, Singer J, Meltzer H, & the Clozapin Collaborative Study Group (1988). Clozapine for the treatment-resistent schizophrenic. Archives of General Psychiatry 45: 789–796, 1988

    Google Scholar 

  • Johnstone EC, Crow TJ, Frith CD, Camey MWP, Price JS: Mechanisms of the antipsychotic effect in the treatment of acute schizophrenia. Lancet I: 848–851, 1978

    Google Scholar 

  • Kay SR: Longitudinal course of negative symptoms in schizophrenia. In: Greden JF, Tandon R (eds): Negative Schizophrenic Symptoms: Pathophysiology and Clinical Implications, pp. 21–40. Washington DC, American Psychiatric Press, 1991

    Google Scholar 

  • Kay SR, Fiszbein A, Opler LA: The Positive and Negative Syndrome Scale (PANSS) for Schizophrenia. Schizophrenia Bulletin 13: 152–160, 1987

    Google Scholar 

  • Kayton L, Beck J, Koh S: Postpsychotic state, convalescent environment, and therapeutic relationship in schizophrenic outcome. American Journal of Psychiatry 133: 1269–1274, 1976

    PubMed  CAS  Google Scholar 

  • Kendell RE: The Role of Diagnosis in Psychiatry. Osney Mead, Oxford, Blackwell Scientific Publications, 1975

    Google Scholar 

  • Kick AH: Psychopathologie and Verlauf der postakuten Schizophrenie (Psychopathology and Course of Postacute Schizophrenia). Berlin, Springer, 1991

    Google Scholar 

  • Kitamura T, Suga R: Depressive and negative symptoms in major psychiatric disorders. Comprehensive Psychiatry 32: 88–94, 1991

    Article  PubMed  CAS  Google Scholar 

  • Klosterkötter J: Basissymptome and Endphänomene der Schizophrenie (Basic symptoms and final phenomena of schizophrenia). Berlin, Springer, 1988

    Google Scholar 

  • Knight RA, Elliot D, Freedman, E: Short term visual memory in schizophrenics. Journal of Abnormal Psychology 94: 427–443, 1985

    Article  PubMed  CAS  Google Scholar 

  • Knight RA, Elliot D, Roff DJ, Watson CG: Concurrent and predictive validity of components of disordered thinking. Schizophrenia Bulletin 12: 427–446, 1986

    PubMed  CAS  Google Scholar 

  • Knights A, Hirsch SR: “Revealed” depression and drug treatment for schizophrenia. Archives of General Psychiatry 38: 806–811, 1981

    PubMed  CAS  Google Scholar 

  • Kraepelin E: Psychiatrie, 6th ed., Leipzig, Barth, 1899

    Google Scholar 

  • Kulhara P, Chadda R: A study of negative symptoms in schizophrenia and depression. Comprehensive Psychiatry 28: 229–235, 1987

    Article  PubMed  CAS  Google Scholar 

  • Lewine RJJ, Fogg L, Meltzer HY: Assessment of negative and positive symptoms in schizophrenia. Schizophrenia Bulletin 9: 368–376, 1983

    PubMed  CAS  Google Scholar 

  • Liddle PF, Morris DL: Schizophrenic syndromes and frontal lobe performance. British Journal of Psychiatry 158: 340–345, 1991

    Article  PubMed  CAS  Google Scholar 

  • Marjot DH: Depression following fluphenazine treatment. British Medical Journal 3: 780, 1969

    Article  PubMed  CAS  Google Scholar 

  • Moller HJ, von Zerssen D: Depressive states occurring during the neuroleptic treatment of schizophrenia. Schizophrenia Bulletin 8: 109–117, 1982

    PubMed  CAS  Google Scholar 

  • Mundt Ch, Fiedler P, Pracht B, Rettich R: (1985). InSka (Intentionalitätsskala)—ein neues psychometrisches Instrument zur quantitativen Erfassung der schizophrenen Residualsymptomatik (InSka—a new questionnaire for the quantitative registration of schizophrenic residual symptomatology). Nervenarzt 56: 146–149, 1985

    Google Scholar 

  • Mundt Ch, Kasper S: Zur Schizophreniespezifität von negativen and Basissymptomen (specifity of negative and basic symptoms in schizophrenia). Nervenarzt 58: 489–495, 1987

    PubMed  CAS  Google Scholar 

  • Mundt Ch, Kasper S, Huerkamp M: The diagnostic specificity of negative symptoms and their psychopathological context. British Journal of Psychiatry 155 (Suppl 7): 32–36, 1989

    Google Scholar 

  • Nestadt G, McHugh PR: The frequency of and specifity of some “negative” symptoms. In: Huber G (ed): Basisstadien endogener Psychosen and das Borderline-Problem, pp. 183–193. Stuttgart, Schattauer, 1985

    Google Scholar 

  • Nuechterlein KH, Edell WS, Norris M, Dawson ME: Attentional vulnerability indicators, thought disorder, and negative symptoms. Schizophrenia Bulletin 12: 408–426, 1986

    PubMed  CAS  Google Scholar 

  • Nuechterlein KH, Zaucha KM:Processing abnormalities in patients and high-risk children. In: Straube ER, Hahlweg K (eds): Schizophrenia. Concepts, Vulnerability, and Intervention, pp. 77–96. Springer, Berlin, 1990

    Google Scholar 

  • Owens DGC, Johnstone EC: The disabilities of chronic schizophrenia—their nature and the factors contributing to their development. British Journal of Psychiatry 136: 384–395, 1980

    Article  Google Scholar 

  • Pfohl B, Andreasen N: Schizophrenia: diagnosis and classification. In: Hales FA (ed): Psychiatry update, vol. 5, pp. 38–51. Washington DC, American Psychiatric Press, 1986

    Google Scholar 

  • Pfohl B, Winokur G: The micropsychopathology of hebephrenic/catatonic schizophrenia. Journal of Nervous and Mental Disease 171: 296–300, 1983

    Article  PubMed  CAS  Google Scholar 

  • Pfohl B, Winokur G: The evaluation of symptoms in institutionalized hebephrenic/catatonic schizophrenics. British Journal of Psychiatry 141: 567–572, 1982

    Article  PubMed  CAS  Google Scholar 

  • Place J, Gilmore GC: Perceptual organization in schizophrenia. Journal of Abnormal Psychology 89: 409–418, 1980

    Article  PubMed  CAS  Google Scholar 

  • Plananski K, Johnston R: Depressive syndrome in schizophrenia. Acta Psychiatrica Scandinavica 57: 207–218, 1978

    Article  Google Scholar 

  • Pogue-Geile MF, Harrow M: Negative and positive symptoms in schizophrenia and depression: a follow up. Schizophrenia Bulletin 10: 371–387, 1984

    PubMed  CAS  Google Scholar 

  • van Putten T, May PRA: “Akinetic depression” in schizophrenia. Archives of General Psychiatry 35: 1101–1107, 1978

    PubMed  Google Scholar 

  • Rifkin A, Quitkin F, Klein SF: Akinesia, a poorly recognized drug-induced extrapyramidal behaviour disorder. Archives of General Psychiatry 32: 672–674, 1975

    Google Scholar 

  • Rosen WG, Mohs RC, Johns CA, Small NS, Kendler KS, Horvath TB, Davis KL: Positive and negative symptoms in schizophrenia. Psychiatry Research 13: 277–284, 1984

    Article  PubMed  CAS  Google Scholar 

  • Rosvold HE, Mirsky A, Sarason I, Bransome ED, Beck LH: A continuous performance test of brain damage. Journal of Consulting Psychology 20: 343–350, 1956

    Article  PubMed  Google Scholar 

  • Salzinger K, Portnoy S, Feldmann RS: Communicability deficit in schizophrenics resulting from a more general deficit. In: Schwartz S (ed): Language and Cognition in Schizophrenia, pp. 35–53. Hillsdale, Erlbaum, 1978

    Google Scholar 

  • Salzinger K, Portnoy S, Feldmann RS: Verbal behavior of schizophrenics and normal subjects. Annals of the New York Academy of Sciences 105: 845–860, 1964

    Article  PubMed  CAS  Google Scholar 

  • Sass H: The historical evolution of the concept of negative symptoms in schizophrenia. British Journal of Psychiatry 155 (Suppl 7): 26–31, 1989

    Google Scholar 

  • Schneider K: Psychischer Befund and psychiatrische Diagnose (Mental state and psychiatric diagnosis). Leipzig, Thieme, 1939

    Google Scholar 

  • Segal M, Ropschitz DH: Depressive changes after fluphenazine treatment. British Medical Journal 4: 169, 1969

    Article  PubMed  CAS  Google Scholar 

  • Shanfield S, Tucker GJ, Harrow M, Detre T: The schizophrenic patient and depressive symptomatology. Journal of Nervous and Mental Disease 151: 203–210, 1970

    Article  PubMed  CAS  Google Scholar 

  • Silverstein ML, Arzt, AT: Neuropsychological dysfunction in schizophrenia. Journal of Nervous and Mental Disease 173: 341–346, 1985

    Article  PubMed  CAS  Google Scholar 

  • Siris SG, Rifkin A, Reardon GT, Endicott J, Pereira DH, Hayes R, Casey E: Course-related depressive syndromes in schizophrenia. American Journal of Psychiatry 141: 1254–1257, 1983

    Google Scholar 

  • Sommers E: “Negative symptoms”: conceptual and methodological problems. Schizophrenia Bulletin 11: 364–378, 1985

    PubMed  CAS  Google Scholar 

  • Spring B, Lemon M, Fergeson P: Vulnerabilities to schizophrenia: information-processing markers, In: Straube ER, Hahlweg K (eds): Schizophrenia. Concepts, Vulnerability, and Intervention, pp. 97–114. Berlin, Springer, 1990

    Google Scholar 

  • Strauss JS, Carpenter WT, Bartko JJ: The diagnosis and understanding of schizophrenia, II: speculations upon the process that underlie schizophrenic symptoms and signs. Schizophrenia Bulletin 11: 61–76, 1974

    PubMed  Google Scholar 

  • Strian F, Heger R, Klicpera C: The time structure of depressive mood in schizophrenic patients. Acta Psychiatrica Scandinavica 65: 66–73, 1982

    Article  PubMed  CAS  Google Scholar 

  • Süllwold L, Huber G: Schizophrene Basisstörungen (Basic disturbances in schizophrenia). Berlin, Springer, 1986

    Google Scholar 

  • Tandon R, Goldman RS, Goodson J, Greden JF: Mutability and relationship between positive and negative symptoms during neuroleptic treatment in schizophrenia. Biological Psychiatry 27: 1323–1326, 1990

    Article  PubMed  CAS  Google Scholar 

  • Tandon R, Greden JF: Conclusion: is integration possible? In: Greden JF, Tandon R (eds): Negative Schizophrenic Symptoms: Pathophysiology and Clinical Implications, pp. 233–239. Washington DC, American Psychiatric Press, 1991

    Google Scholar 

  • Taylor WL: Cloze procedure: a new tool for measuring readability. Journalism Quarterly 30: 415–433, 1953

    Google Scholar 

  • Wagner M: Experimentelle Verfahren zur Aufmerksamkeitsprüfung (EVA): CPT and SAT (Experimental measures of attention: CPT and SAT). München, Psychiatrische Universitätsklinik, 1989

    Google Scholar 

  • Weiner RU, Opler LA, Kay SR, Merriam AE, Papouchis M: Visual information processing in positive, mixed, and negative schizophrenic syndromes. Journal of Nervous and Mental Disease 178: 616–626, 1990

    Article  PubMed  CAS  Google Scholar 

  • Wing JK: A standard form of psychiatric Present-State Examination and a method for standardizing the classification of symptoms. In: Hare EH, Wing JK (eds): Psychiatric Epidemiology: An International Symposium, pp. 93–108. London, Oxford University Press, 1970

    Google Scholar 

  • Wing JK: Schizophrenia: Towards a New Synthesis. London, Academic Press, 1978

    Google Scholar 

  • Wing JK, Brown GW: Institutionalization and Schizophrenia. Cambridge, Cambridge University Press, 1970

    Book  Google Scholar 

  • Wohlberg GW, Kornetsky C: Sustained attention in remitted schizophrenics. Archives of General Psychiatry 28: 533–537, 1973

    PubMed  CAS  Google Scholar 

Download references

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Barnett, W., Mundt, C. (1992). Are Latent Thought Disorders the Core of Negative Schizophrenia?. In: Spitzer, M., Uehlein, F., Schwartz, M.A., Mundt, C. (eds) Phenomenology, Language & Schizophrenia. Springer, New York, NY. https://doi.org/10.1007/978-1-4613-9329-0_15

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