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Latent trait modelling of symptoms of schizophrenia

Published online by Cambridge University Press:  09 July 2009

R. C. Bell*
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
L. H. Low
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
H. J. Jackson
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
P. L. Dudgeon
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
D. L. Copolov
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
B. S. Singh
Affiliation:
NH & MRC Schizophrenia Unit, Mental Health Research Institute of Victoria, Australia
*
1 Address for correspondence: Dr Richard C. Bell, Mental Health Research Institute of Victoria, Private Bag 3, Parkville, VIC 3052, Australia

Synopsis

Latent trait models were fitted to data for 149 schizophrenic or schizophreniform in-patients rated on the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) using the Rasch Extended Logistic Model. It was found that a reduction in the numbers of rating categories, from six to three or four led to consistencies in response while deletion of several items led to consistent scales of symptoms that accorded with an item response characterization. Behaviours included in the final scales varied in the numbers of categories, and in the range of symptom level covered by a category. Relationships between scores representing symptoms were found to be modelled better by a factor structure that included a third overlapping ‘cognitive’ factor in addition to the now traditional positive and negative factors, than by the original positive and negative factors alone.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1994

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References

American Psychiatric Association (1980). Diagnostic and Statistical Manual of Mental Disorders (3rd edn) APA: Washington, DC.Google Scholar
Andrich, D. (1985). An elaboration of Guttman scales in Rasch models for measurement. In Sociological Methodology 1985 (ed. Brandon-Tuma, N.), pp. 3380. Jossey-Bass: San Francisco.Google Scholar
Andrich, D. & van Schoubreck, L. (1989). The General Health Questionnaire: a psychometric analysis using latent trait theory. Psychological Medicine 19, 469485.CrossRefGoogle ScholarPubMed
Andreasen, N. C. (1979). The clinical assessment of thought, language, and communication disorders. Archives of General Psychiatry 36, 13151325.Google Scholar
Andreasen, N. C. (1982 a). Negative symptoms in schizophrenia: definition and reliability. Archives of General Psychiatry 39, 784788.Google Scholar
Andreasen, N. C. (1982 b). Negative versus positive schizophrenia: definition and validation. Archives of General Psychiatry 39, 789794.Google Scholar
Andreasen, N. C. (1983). The Scale for the Assessment of Negative Symptoms. University of Iowa: Iowa City, IA.Google Scholar
Andreasen, N. C. (1984). The Scale for the Assessment of Positive Symptoms. University of Iowa: Iowa City, IA.Google Scholar
Andreasen, N. C., Flaum, M., Swayze, V. W., Tyrrell, G. & Arndt, S. (1990). Positive and negative symptoms in schizophrenia. Archives of General Psychiatry 47, 615621.Google Scholar
Crow, T. J. (1980). Molecular pathology of schizophrenia: more than one disease process? British Medical Journal 280, 6668.CrossRefGoogle ScholarPubMed
Crow, T. J. (1985). The two-syndrome concept: origins and current status. Schizophrenia Bulletin 11, 671686.Google Scholar
Cudeck, R. (1989). Analysis of correlation matrices using covariance structure models. Psychological Bulletin 105, 317327.CrossRefGoogle Scholar
de Leon, J., Wilson, W. H. & Simpson, G. M. (1989). Measurement of negative symptoms in schizophrenia. Psychiatric Developments 3, 211234.Google Scholar
Duncan-Jones, P., Grayson, D. A. & Moran, P. A. P. (1986). The utility of latent trait models in psychiatric epidemiology. Psychological Medicine 16, 391405.CrossRefGoogle ScholarPubMed
Fraser, C. & McDonald, R. P. (1988). COSAN: Covariance structure analysis. Multivariate Behavioral Research, 23, 263265.Google Scholar
Grayson, D. A. (1987). Can categorical and dimensional views of psychiatric illness be distinguished? British Journal of Psychiatry 151, 355361.Google Scholar
Jorgensen, P. & Jensen, J. (1990). A dimensional approach to severe delusional psychoses. Psychopathology 23, 914.Google ScholarPubMed
Kay, S. R. (1990). Positive-negative symptom assessment in schizophrenia: psychometric issues and scale comparisons. Psychiatric Quarterly 61, 163178.Google Scholar
Kay, S. R. & Sevy, S. (1990). Pyramidical model of schizophrenia. Schizophrenia Bulletin 16, 537545.CrossRefGoogle ScholarPubMed
Kay, S. R., Opler, L. A. & Fiszbein, A. (1986). Significance of positive and negative syndromes in chronic schizophrenia. British Journal of Psychiatry 149, 439448.Google Scholar
Lewine, R. R. J., Fogg, L. & Meltzer, H. Y. (1983). Assessment of negative and positive symptoms in schizophrenia. Schizophrenia Bulletin 9, 368376.CrossRefGoogle ScholarPubMed
Lenzenweger, M. F., Dworkin, R. H. & Wethington, E. (1989). Models of positive and negative symptoms in schizophrenia: an empirical evaluation of latent structures. Journal of Abnormal Psychology 98, 6270.Google Scholar
Liddle, P. F. (1986). The symptoms of chronic schizophrenia: a reexamination of the positive-negative dichotomy. British Journal of Psychiatry 151, 145151.Google Scholar
Liddle, P. F. (1987). Schizophrenic syndomes, cognitive performance and neurological dysfunction. Psychological Medicine 17, 4957.CrossRefGoogle Scholar
Lumsden, J. (1976). Test theory. Annual Review of Psychology 27, 251280.CrossRefGoogle Scholar
McDonald, R. P. & Marsh, H. W. (1990). Choosing a multivariate model: noncentrality and goodness of fit. Psychological Bulletin 107, 247255.Google Scholar
Maier, W., Philipp, M. & Heuser, I. (1986). Dimensional assessment of endogeneous depression based on a polydiagnostic approach. Psychopathology 19, 267275.Google Scholar
Rasch, G. (1960). Probabilistic Models for Some Intelligence and Attainment Tests. Danish Institute for Educational Research: Copenhagen.Google Scholar
Sommers, A. A. (1985). Negative symptoms. conceptual and methodological problems. Schizophrenia Bulletin 11, 364379.CrossRefGoogle ScholarPubMed
Tucker, L. R. & Lewis, C. (1973). The reliability coefficient for maximum likelihood factor analysis. Psychometrika 38, 110.Google Scholar