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Combining dimensional and categorical representation of psychosis: the way forward for DSM-V and ICD-11?

Published online by Cambridge University Press:  23 July 2009

A. Demjaha*
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
K. Morgan
Affiliation:
Department of Psychology, Westminster University, London, UK
C. Morgan
Affiliation:
Centre for Public Mental Health, Health Service and Population Research Department, Institute of Psychiatry, King's College, London, UK
S. Landau
Affiliation:
Department of Biostatistics, Institute of Psychiatry, King's College, London, UK
K. Dean
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
A. Reichenberg
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
P. Sham
Affiliation:
Department of Psychiatry and State Key Laboratory for Cognitive and Brain Sciences, LKS Faculty of Medicine, the University of Hong Kong
P. Fearon
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
G. Hutchinson
Affiliation:
Psychiatry Unit, University of the West Indies, Trinidad
P. B. Jones
Affiliation:
Department of Psychiatry, University of Cambridge, Cambridge, UK
R. M. Murray
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
P. Dazzan
Affiliation:
Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
*
*Address for correspondence: A. Demjaha, Institute of Psychiatry, Box PO63, De Crespigny Park, London SE5 8AF, UK. (Email: a.demjaha@iop.kcl.ac.uk)

Abstract

Background

There is good evidence that psychotic symptoms segregate into symptom dimensions. However, it is still unclear how these dimensions are associated with risk indicators and other clinical variables, and whether they have advantages over categorical diagnosis in clinical practice. We investigated symptom dimensions in a first-onset psychosis sample and examined their associations with risk indicators and clinical variables. We then examined the relationship of categorical diagnoses to the same variables.

Method

We recruited 536 patients as part of a population-based, incidence study of psychosis. Psychopathology was assessed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). A principal axis factor analysis was performed on symptom scores. The relationship of dimension scores with risk indicators and with clinical variables was then examined employing regression analyses. Finally, regression models were compared to assess the contribution of dimensions versus diagnosis in explaining these variables.

Results

Factor analysis gave rise to a five-factor solution of manic, reality distortion, negative, depressive and disorganization symptom dimensions. The scores of identified dimensions were differentially associated with specific variables. The manic dimension had the highest number of significant associations; strong correlations were observed with shorter duration of untreated psychosis, acute mode of onset and compulsory admission. Adding dimensional scores to diagnostic categories significantly increased the amount of variability explained in predicting these variables; the reverse was also true but to a lesser extent.

Conclusions

Categorical and dimensional representations of psychosis are complementary. Using both appears to be a promising strategy in conceptualising psychotic illnesses.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2009

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References

Allardyce, J, McCreadie, GR, Morrison, G, Van Os, J (2007). Do symptom dimensions or categorical diagnoses best discriminate between known risk factors for psychosis? Social Psychiatry and Psychiatric Epidemiology 42, 429437.CrossRefGoogle ScholarPubMed
Andreasen, NC, Olsen, S (1982). Negative v. positive schizophrenia: definition and validation. Archives of General Psychiatry 39, 789794.CrossRefGoogle ScholarPubMed
Arango, C, Kirkpatrick, B, Buchanan, RW (2000). Neurological signs and the heterogeneity of schizophrenia. American Journal of Psychiatry 157, 560565.CrossRefGoogle ScholarPubMed
Arndt, S, Alliger, RJ, Andreasen, NC (1991). The distinction of positive and negative symptoms. The failure of a two-dimensional model. British Journal of Psychiatry 158, 317322.CrossRefGoogle ScholarPubMed
Bilder, RM, Mukherjee, S, Reider, RO, Panduragi, AK (1985). Symptomatic and neuropsychological components of defect states. Schizophrenia Bulletin 11, 409419.CrossRefGoogle ScholarPubMed
Boks, MP, Liddle, PF, Burgerhof, JGM, Knegtering, R, Van den Bosch, RJ (2004). Neurological soft signs discriminating mood disorders from first episode schizophrenia. Acta Psychiatrica Scandinavica 110, 2935.CrossRefGoogle ScholarPubMed
Brown, KW, White, T (1992). Syndromes of chronic schizophrenia and some clinical correlates. British Journal of Psychiatry 161, 317322.CrossRefGoogle ScholarPubMed
Buchanan, RW, Heinrichs, DW (1989). The Neurological Evaluation Scale (NES): a structured instrument for the assessment of neurological signs in schizophrenia. Psychiatry Research 27, 335350.CrossRefGoogle Scholar
Crow, TJ (1980). Molecular pathology of schizophrenia: more than one disease process? British Medical Journal 280, 6668.CrossRefGoogle ScholarPubMed
Cardno, AG, Sham, PC, Murray, RM, McGuffin, P (2001). Twin study of symptom dimensions in psychoses. British Journal of Psychiatry 179, 3945.CrossRefGoogle ScholarPubMed
Comrey, AL, Lee, HB (1992). A First Course in Factor Analysis, 2nd edn.Lawrence Erlbaum Associates: Hillsdale, NJ.Google Scholar
Costello, AB, Osborne, JW (2005). Best practices in exploratory factor analysis: Four recommendations for getting the most from your analysis. Practical Assessment, Research & Evaluation 10, 19.Google Scholar
Cuesta, MJ, Peralta, V, Gil, P, Artamendi, M (2003). Psychopathological dimensions in first-episode psychoses. From the trunk to the branches and leaves. European Archives of Psychiatry and Clinical Neuroscience 253, 7379.CrossRefGoogle Scholar
Dazzan, P, Morgan, KD, Orr, KG, Hutchinson, G, Xavier Chitnis, C, Suckling, J, Fearon, P, Salvo, J, McGuire, PK, Mallett, RM, Jones, PB, Leff, J, Murray, RM (2004). The structural brain correlates of neurological soft signs in AESOP first-episode psychoses study. Brain 127, 143153.CrossRefGoogle ScholarPubMed
Dazzan, P, Morgan, K, Chitnis, X, Suckling, J, Morgan, C, Fearon, P, McGuire, PK, Jones, P, Leff, J, Murray, RM (2006). The structural brain correlates of neurological soft signs in healthy individuals. Cerebral Cortex 16, 12251231.CrossRefGoogle ScholarPubMed
Dikeos, DG, Wickham, H, McDonald, C, Walshe, M, Sigmundsson, TH, Bramon, E, Grech, A, Toulopoulou, T, Murray, R, Sham, P (2006). Distribution of symptom dimensions across Kraepelinian divisions. British Journal of Psychiatry 189, 346353.CrossRefGoogle ScholarPubMed
Drake, RJ, Dunn, G, Tarrier, N, Haddock, G, Haley, C, Lewis, S (2003). The evolution of symptoms in the early course of non-affective psychosis. Schizophrenia Research 63, 171179.CrossRefGoogle ScholarPubMed
Edwards, J, McGorry, PD, Wadell, FM, Harrigan, SM (1999). Enduring negative symptoms in first-episode psychosis: comparison of six methods using follow-up data. Schizophrenia Research 40, 147158.CrossRefGoogle ScholarPubMed
Emsley, RA, Oosthuizen, P, Joubert, A, Roberts, MC, Stein, DJ (1999). Depressive and anxiety symptoms in patients with schizophrenia and schizophreniform disorder. Journal of Clinical Psychiatry 60, 747751.CrossRefGoogle ScholarPubMed
Fearon, P, Kirkbride, JK, Morgan, C, Dazzan, P, Morgan, K, Lloyd, T, Hutchinson, G, Tarrant, J, Fung, A, Holloway, J, Mallett, R, Harrison, G, Leff, J, Jones, PB, Murray, RM (2006). Incidence of schizophrenia and other psychoses in ethnic minority groups: results from the MRC AESOP study. Psychological Medicine 36, 15411550.CrossRefGoogle ScholarPubMed
Fenton, WS, McGlashan, TH (1991). Natural history of schizophrenia subtypes: II. Positive and negative symptoms and long-term course. Archives of General Psychiatry 48, 978986.CrossRefGoogle ScholarPubMed
Grube, BS, Bilder, RM, Goldman, RS (1998). Meta-analysis of symptom factors in schizophrenia. Schizophrenia Research 31, 113120.CrossRefGoogle ScholarPubMed
Guerra, A, Fearon, P, Sham, P, Jones, P, Lewis, S, Mata, I, Murray, R (2002). The relationship between predisposing factors, premorbid function and symptom dimensions in psychosis: an integrated approach. European Psychiatry 17, 311320.CrossRefGoogle ScholarPubMed
Harris, MG, Henry, LP, Harrigan, SM, Purcell, R, Schwartz, OS, Farrelly, SE, Prosser, AL, Jackson, HJ, McGorry, PD (2005). The relationship between duration of untreated psychosis and outcome: an eight-year prospective study. Schizophrenia Research 79, 8593.CrossRefGoogle ScholarPubMed
Harrison, G, Croudace, T, Mason, P, Glazebrook, C, Medley, I (1996). Predicting long-term outcome in schizophrenia. Psychological Medicine 26, 697705.CrossRefGoogle ScholarPubMed
Hutchinson, G, Takei, N, Sham, P, Harvey, I, Murray, RM (1999). Factor analysis of symptoms in schizophrenia: differences between white and Caribbean patients in Camberwell. Psychological Medicine 29, 607612.CrossRefGoogle ScholarPubMed
Jablensky, A, Kendell, RE (2002). Criteria for assessing a classification in psychiatry. In The Future of Psychiatric Diagnosis and Classification (ed. Maj, M, Gaebel, W, López-Ibor, J and Sartorius, N.), pp. 124. Wiley: Chichester.Google Scholar
Kay, SR, Fiszbein, A, Opler, LA (1987). The Positive and Negative Syndrome Scale (PANSS) for schizophrenia. Schizophrenia Bulletin 13, 261275.CrossRefGoogle ScholarPubMed
Kitamura, T, Okazaki, Y, Fujinawa, A, Takayanagi, I, Kasahara, Y (1995). Symptoms of psychosis. A factor-analytic study. British Journal of Psychiatry 166, 236240.CrossRefGoogle ScholarPubMed
Lane, A, Kinsella, A, Murphy, P, Byrne, M, Keenan, J, Colgan, K, Cassidy, B, Sheppard, N, Horgan, R, Waddington, JL, Larkin, C, O'Callaghan, E (1997). The anthropometric assessment of dysmorphic features in schizophrenia as an index of its developmental origins. Psychological Medicine 27, 11551164.CrossRefGoogle ScholarPubMed
Larsen, TK, Moe, LC, Vibe-Hansen, L, Johannessen, JO (2000). Premorbid functioning versus duration of untreated psychosis in 1 year outcome in first-episode psychosis. Schizophrenia Research 45, 19.CrossRefGoogle ScholarPubMed
Liddle, PF (1987). The symptoms of chronic schizophrenia. A re-examination of the positive–negative dichotomy. British Journal of Psychiatry 151, 145151.CrossRefGoogle ScholarPubMed
Liddle, PF, Barnes, TR (1990). Syndromes of chronic schizophrenia. British Journal of Psychiatry 157, 558561.CrossRefGoogle ScholarPubMed
Liddle, PF, Ngan, ETN, Duffield, G, Kho, K, Warren, AJ (2002). The signs and symptoms of psychotic illness: a rating scale. British Journal of Psychiatry 180, 4550.CrossRefGoogle ScholarPubMed
Lindenmayer, JP, Grochowski, S, Hyman, RB (1995). Five factor model of schizophrenia: replication across samples. Schizophrenia Research 14, 229234.CrossRefGoogle ScholarPubMed
Malla, A, Payne, J (2005). First-episode psychosis: psychopathology, quality of life, and functional outcome. Schizophrenia Bulletin 31, 650671.CrossRefGoogle ScholarPubMed
Malla, AK, Norman, RMG, Manchanda, R, Ahmed, MR, Scholten, D, Harricharan, R, Cortese, L, Takhar, J (2002). One year outcome in first episode psychosis: influence of DUP and other predictors. Schizophrenia Research 54, 231242.CrossRefGoogle ScholarPubMed
Malla, AK, Norman, RMG, Williamson, PWC, Cortese, L, Diaz, F (1993). Three syndrome concept of schizophrenia: a factor analytic study. Schizophrenia Research 10, 143150.CrossRefGoogle ScholarPubMed
McGlashan, TH, Fenton, WS (1993). Subtype progression and pathophysiologic deterioration in early schizophrenia. Schizophrenia Bulletin 19, 7184.CrossRefGoogle ScholarPubMed
McGorry, P, Bell, RC, Dudgeon, PL, Jackson, HJ (1998). The dimensional structure of first episode psychosis: an exploratory factor analysis. Psychological Medicine 28, 935947.CrossRefGoogle ScholarPubMed
McIntosh, AM, Forrester, A, Lawrie, SM, Byrne, M, Harper, A, Kestelman, JN, Best, K, Miller, P, Johnstone, EC, Owens, DGC (2001). A factor model of the functional psychoses and the relationship of factors to clinical variables and brain morphology. Psychological Medicine 31, 159171.CrossRefGoogle ScholarPubMed
Mellers, JDC, Sham, P, Jones, PB, Toone, BK, Murray, RM (1996). A factor analytic study of symptoms in acute schizophrenia. Acta Psychiatrica Scandinavica 93, 9298.CrossRefGoogle ScholarPubMed
Morgan, C, Fearon, P, Hutchinson, G, Mckenzie, K, Lappin, JM, Abdul, AR, Morgan, K, Dazzan, P, Boydell, J, Harrison, G, Craig, T, Leff, J, Jones, P, Murray, RM (2006). Duration of untreated psychosis and ethnicity in the AESOP first-onset psychosis study. Psychological Medicine 36, 239247.CrossRefGoogle ScholarPubMed
Murray, RM, Lewis, SW (1987). Is schizophrenia a neurodevelopmental disorder? British Medical Journal 295, 681682.CrossRefGoogle ScholarPubMed
Nelson, HE, Willison, JR (1991). The Revised National Adult Reading Test – Test Manual. NFER-Nelson: Windsor.Google Scholar
Norman, R, Malla, AK, Morrison-Stewart, SL, Helmes, E, Williamson, PC, Thomas, J, Cortese, L (1997). Neuropsychological correlates of syndromes in schizophrenia. British Journal of Psychiatry 170, 134139.CrossRefGoogle ScholarPubMed
O'Callaghan, E, Buckley, P, Madigan, C, Redmond, O, Stack, P, Kinsella, A, Larkin, C, Ennis, JT, Waddington, JL (1995). The relationship of minor physical anomalies and other putative indices of developmental disturbance in schizophrenia to abnormalities of cerebral structure on magnetic resonance imaging. Biological Psychiatry 38, 516524.CrossRefGoogle ScholarPubMed
Peralta, V, Cuesta, MJ (2001). How many and which are the psychopathological dimensions in schizophrenia? Issues influencing their ascertainment. Schizophrenia Research 49, 269285.CrossRefGoogle ScholarPubMed
Peralta, V, Cuesta, MJ, De Leon, J (1994). An empirical analysis of latent structures underlying schizophrenic symptoms: a four syndrome model. Biological Psychiatry 36, 726736.CrossRefGoogle ScholarPubMed
Peralta, V, Cuesta, MJ, Giraldo, C, Cardenas, A, Gonzalez, F (2002). Classifying psychotic disorders: issues regarding categorical vs. dimensional approaches and time frame to assess symptoms. European Archives in Psychiatry and Clinical Neuroscience 252, 1218.CrossRefGoogle ScholarPubMed
Peralta, V, De Leon, J, Cuesta, MJ (1992). Are there more than two syndromes in schizophrenia? A critique of the positive–negative dichotomy. British Journal of Psychiatry 161, 335343.CrossRefGoogle ScholarPubMed
Rietkerk, T, Boks, MP, Sommer, IE, Liddle, PF, Ophoff, RA, Kahn, RS (2008). The genetics of symptom dimensions of schizophrenia: review and meta-analysis. Schizophrenia Research 102, 197205.CrossRefGoogle ScholarPubMed
Rosenman, S, Korten, A, Medway, J, Evans, M (2003). Dimensional vs. categorical diagnosis in psychosis. Acta Psychiatrica Scandinavica 107, 378384.CrossRefGoogle ScholarPubMed
Rotakonda, S, Gorman, JM, Yale, SA, Amador, XF (1998). Characterization of psychotic conditions. Use of the domains of psychopathology model. Archives of General Psychiatry 55, 7581.CrossRefGoogle Scholar
Sanfilipo, M, Lafargue, T, Rusinek, H, Arena, L, Loneragan, C, Lautin, A, Feiner, D, Rotrosen, J, Wolkin, A (2000). Volumetric measure of the frontal and temporal lobe regions in schizophrenia: relationship to negative symptoms. Archives of General Psychiatry 57, 471480.CrossRefGoogle ScholarPubMed
Silver, H, David, D, Kaplan, M, Hadjez, J, Tubi, N, Darnel, A, Calev, A, Lerer, B (1993). Factor analysis of schizophrenic symptoms and comparison of different ratings scales. Schizophrenia Research 10, 6775.CrossRefGoogle Scholar
Smith, DA, Mar, CM, Turoff, BK (1998). The structure of schizophrenic symptoms: a meta-analytic confirmatory factor analysis. Schizophrenia Research 31, 5770.CrossRefGoogle ScholarPubMed
Tabachnick, BG, Fidell, LS (1989). Using Multivariate Statistics, 2nd edn.Harper Collins: New York.Google Scholar
Van der Gaag, M, Cuijpers, A, Hoffman, T, Remijsen, M, Hijman, R, de Haan, L, van Meijel, B, van Harten, PN, Valmaggia, L, de Hert, M, Wiersma, D (2006 a). The five-factor model of the Positive and Negative Syndrome Scale I: confirmatory factor analysis fails to confirm 25 published five-factor solutions. Schizophrenia Research 85, 273279.CrossRefGoogle ScholarPubMed
Van der Gaag, M, Hoffman, T, Remijsen, M, Hijman, R, de Haan, L, van Meijel, B, van Harten, PN, Valmaggia, L, de Hert, M, Cuijpers, A, Wiersma, D (2006 b). The five-factor model of the Positive and Negative Syndrome Scale II: a ten-fold cross-validation of a revised model. Schizophrenia Research 85, 280287.CrossRefGoogle Scholar
Van Os, J, Fahy, TA, Jones, P, Harvey, I, Sham, P, Lewis, S, Bebbington, P, Toone, B, Williams, M, Murray, R (1996). Psychopathological syndromes in the functional psychoses: associations with course and outcome. Psychological Medicine 26, 161176.CrossRefGoogle ScholarPubMed
Van Os, J, Gilvarry, C, Bale, R, Van Horn, E, Tattan, T, White, I, Murray, R (1999). A comparison of the utility of dimensional and categorical representations of psychosis. UK700 Group. Psychological Medicine 29, 595606.CrossRefGoogle ScholarPubMed
Van Os, J, Marcelis, M, Sham, P, Jones, P, Gilvary, K, Murray, R (1997). Psychopathological syndromes and familial morbid risk of psychosis. British Journal of Psychiatry 170, 241246.CrossRefGoogle ScholarPubMed
Van Os, J, Verdoux, H (2003). Diagnosis and classification in schizophrenia: categories versus dimensions, distributions versus disease. In The Epidemiology of Schizophrenia (ed. Murray, R. M., Jones, P. B., Susser, E., van Os, J. and Cannon, M.), pp. 364410. Cambridge University Press: Cambridge.Google Scholar
Wickham, H, Walsh, C, Asherson, P, Taylor, C, Sigmundson, T, Gill, M, Owen, MJ, McGuffin, P, Murray, R, Sham, P (2001). Familiality of symptom dimensions in schizophrenia. Schizophrenia Research 47, 223232.CrossRefGoogle ScholarPubMed
Wong, AH, Voruganti, LN, Heslegrave, RJ, Awad, AG (1997). Neurocognitive deficits and neurological signs in schizophrenia. Schizophrenia Research 23, 139146.CrossRefGoogle ScholarPubMed
WHO (1992). SCAN (Schedules for Clinical Assessment in Neuropsychiatry). World Health Organization: Geneva.Google Scholar