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Potuzak M, Ravichandran C, Lewandowski KE, Ongür D, Cohen BM. Categorical vs dimensional classifications of psychotic disorders. Compr Psychiatry 2012; 53:1118-29. [PMID: 22682781 PMCID: PMC3488145 DOI: 10.1016/j.comppsych.2012.04.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 04/11/2012] [Accepted: 04/23/2012] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Both categorical and dimensional methods appear relevant to classifying psychotic disorders; however, there is no clear consensus on the most appropriate categories and dimensions or on the best approach for constructing nosologic criteria that integrate these 2 methods. This review examines the evidence on specific dimensions and categories that would best characterize psychoses. METHOD Entries in the MEDLINE database between 1980 and 2011 were searched for studies of the dimensional and/or categorical structure of psychosis. Studies were included if samples represented a spectrum of psychotic disorders and dimensions/categories were empirically derived using principal components analysis, factor analysis, or latent class analysis. RESULTS Most dimensional studies observed 4 or 5 dimensions within psychosis, with positive, negative, disorganization, and affective symptom domains most frequently reported. Substance abuse, anxiety, early onset/developmental, insight, cognition, hostility, and behavioral/social disturbance dimensions appeared in some studies. Categorical studies suggested 3 to 7 major classes within psychosis, including a class similar to Kraepelin's dementia praecox and one or more classes with significant mood components. Only 2 studies compared the relative fit of empirically derived dimensions and categories within the same data set, and each had significant limitations. CONCLUSION There is relatively consistent evidence on appropriate categories and dimensions for characterizing psychoses. However, the lack of studies directly comparing or combining these approaches provides insufficient evidence for definitive conclusions about their relative merits and integration. The authors provide specific recommendations for designing future studies to identify valid dimensions and/or categories of the psychoses and investigate hybrid approaches to model the structure of the underlying illnesses.
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Affiliation(s)
- Melissa Potuzak
- McLean Hospital, Psychotic Disorders Division, Belmont, MA, 02478, USA
| | - Caitlin Ravichandran
- Harvard Medical School, Department of Psychiatry, Boston, MA, 02215, USA,McLean Hospital, Psychiatric Biostatistics Laboratory, Belmont, MA 02478, USA
| | - Kathryn E. Lewandowski
- McLean Hospital, Psychotic Disorders Division, Belmont, MA, 02478, USA,Harvard Medical School, Department of Psychiatry, Boston, MA, 02215, USA
| | - Dost Ongür
- McLean Hospital, Psychotic Disorders Division, Belmont, MA, 02478, USA,Harvard Medical School, Department of Psychiatry, Boston, MA, 02215, USA
| | - Bruce M. Cohen
- McLean Hospital, Psychotic Disorders Division, Belmont, MA, 02478, USA,Harvard Medical School, Department of Psychiatry, Boston, MA, 02215, USA,Corresponding author. Frazier Research Institute, McLean Hospital, 115 Mill Street, Mail Stop 304, Belmont, MA 02474, USA. Tel.: +1 617 855 3227; fax: +1 617 855 3670. (B.M. Cohen)
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Dikeos DG, Wickham H, McDonald C, Walshe M, Sigmundsson T, Bramon E, Grech A, Toulopoulou T, Murray R, Sham PC. Distribution of symptom dimensions across Kraepelinian divisions. Br J Psychiatry 2006; 189:346-53. [PMID: 17012658 DOI: 10.1192/bjp.bp.105.017251] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Dimensional structures are established for many psychiatric diagnoses, but dimensions have not been compared between diagnostic groups. AIMS To examine the structure of dimensions in psychosis, to analyse their correlations with disease characteristics and to assess the relative contribution of dimensions v. diagnosis in explaining these characteristics. METHOD Factor analysis of the OPCRIT items of 191 Maudsley Family Study patients with schizophrenia, mood disorders with psychosis, schizoaffective disorder, and other psychotic illnesses, followed by regression of disease characteristics from factor scores and diagnosis. RESULTS Five factors were identified (mania, reality distortion, depression, disorganisation, negative); all were more variable in schizophrenia than in affective psychosis. Mania was the best discriminator between schizophrenia and affective psychosis; the negative factor was strongly correlated with poor premorbid functioning, insidious onset and worse course. Dimensions explained more of the disease characteristics than did diagnosis, but the explanatory power of the latter was also high. CONCLUSIONS Kraepelinian diagnostic categories suffice for understanding illness characteristics, but the use of dimensions adds substantial information.
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Affiliation(s)
- Dimitris G Dikeos
- Institute of Psychiatry, SGDP Building, De Crespigny Park, Denmark Hill, London SE5 8AF, UK.
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Ehmann TS, Kragelj T, Smith GN, Higgs E, Flynn SW, Altman S, MacEwan GW, Honer WG. Outcome measurement in pharmacological trials: validity of the Routine Assessment of Patient Progress (RAPP). J Psychopharmacol 2003; 17:425-9. [PMID: 14870955 DOI: 10.1177/0269881103174006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The assessment of outcomes after treatment with antipsychotic medication is fundamental to clinical care and research. The Routine Assessment of Patient Progress (RAPP) is a reliable multidimensional scale that employs nurses' ratings of symptoms and functioning in psychiatric inpatients. The present study sought to extend validity evidence for the RAPP by examining its ability to reflect changes associated with treatment by antipsychotic medications. The use of a different sample in this study also provided the opportunity to replicate earlier validity data collected on the original set of patients. Ninety-seven separate trials were conducted, involving 65 consecutive admissions to a unit that specializes in the assessment and treatment of patients with long standing severe psychiatric disorders. The RAPP, along with the Positive and Negative Syndrome Scale and global measures of severity, were administered at baseline and at the end of each trial. Both factor scores and clinically-derived subscales were analysed for sensitivity to change. Patients were globally rated as improved, unchanged or worsened at the end of the medication trial. Results indicated that the RAPP factor, clinical scale and total scores compared favourably to other outcome measures in patients rated as improved or worse. In patients rated as unchanged, RAPP scores displayed significantly less change than did the PANSS scores. These findings support the validity of the RAPP as an outcome measure in treatment trials.
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Affiliation(s)
- T S Ehmann
- Department of Psychiatry, St Vincent's Hospital, Vancouver, BC, Canada.
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Charles H, John T, Chandy S, Ezhilarasu P, Antonisamy B, Jacob K. Validation of the Routine Assessment of Patient Progress (RAPP) in patients with psychosis in South India. Int J Methods Psychiatr Res 2003; 12:157-64. [PMID: 12953143 PMCID: PMC6878326 DOI: 10.1002/mpr.152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aim of the study was to validate the Routine Assessment of Patient Progress (RAPP), an instrument for assessment by nurses, among patients with psychosis in South India. One hundred consecutive patients with psychosis admitted to the Department of Psychiatry, Christian Medical College, Vellore, India, were assessed on day five and day 19 using the RAPP, the PANSS, and the CGI scales. The correlation of the RAPP with the other scales, its change over time, the inter-rater reliability, and factor structure were assessed. The subscales of RAPP correlated significantly with those of the other scales at intake and at follow-up. The RAPP scores changed significantly after treatment. Its inter-rater reliability as measured by the intra-class correlation coefficient was 0.98. The Cronbach's alpha, used to measure the internal consistency of the scale, was 0.87. The split-half reliability (Spearman-Brown) was 0.89. Principal component analysis with varimax rotation revealed six factors, which explained 67.4% of the variance. Items related to life skills explained a major proportion of the variance. The good psychometric properties, concurrent validity, high inter-rater reliability and sensitivity to change make it a useful instrument for nurses to employ to assess patients with psychoses.
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Affiliation(s)
- H. Charles
- College of Nursing, Christian Medical College, Vellore, India
| | - T. John
- Department of Psychiatry, Christian Medical College, Vellore, India
| | - S. Chandy
- College of Nursing, Christian Medical College, Vellore, India
| | - P. Ezhilarasu
- College of Nursing, Christian Medical College, Vellore, India
| | - B. Antonisamy
- Department of Biostatistics, Christian Medical College, Vellore, India
| | - K.S. Jacob
- Department of Psychiatry, Christian Medical College, Vellore, India
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