Is our concept of schizophrenia influenced by Berkson’s bias?
- 157 Downloads
If both positive and negative dimensions of schizophrenia independently influence need for care, a higher estimate of the comorbidity between these dimensions is expected in clinical samples than would be the case if non–clinical cases were investigated (i. e. Berkson’s bias). The present paper investigates whether positive and negative dimensions independently contribute to mental health care use in a general population sample.
A prospective cohort study was conducted, in which 7076 individuals were interviewed with the Composite International Diagnostic Interview Schedule at baseline and 1 and 3 years later. Lifetime positive and negative psychotic experiences (PPE, NPE) were assessed at baseline. Mental health care use (MHC) was assessed at baseline, and prospectively 1 and 3 years later.
The rating of MHC was strongly associated with NPE and PPE, both retrospectively and prospectively and the effects of both variables remained strong and significant in the analyses with both variables included.
These results, therefore, suggest that the concept of schizophrenia, as a unitary entity with high comorbidity between positive and negative dimensions, is in part the result of Berkson’s bias.
Key wordsschizophrenia continuum Berkson’s bias mental health care comorbidity symptoms
Unable to display preview. Download preview PDF.
- 2.Anthony JC, Folstein M, Romanoski AJ, Von Korff MR, Nestadt GR, Chahal R, Merchant A, Brown CH, Shapiro S, Kramer M,et al. (1985) Comparison of the lay Diagnostic Interview Schedule and a standardized psychiatric diagnosis. Experience in eastern Baltimore. Arch Gen Psychiatry 42(7):667–675PubMedGoogle Scholar
- 3.Berkson J (1950) Are There Two Regressions? J Am Stat Ass 45:164–180Google Scholar
- 5.Bijl RV, Ravelli A, van Zessen G (1998a) Prevalence of psychiatric disorder in the general population: results of The Netherlands Mental Health Survey and Incidence Study (NEMESIS). Soc Psychiatry Psychiatr Epidemiol 33(12):587–595Google Scholar
- 8.Bleuler E (1950) Dementia Praecox or the Group of Schizophrenics. International University Press,New YorkGoogle Scholar
- 15.Hanssen M, Peeters FP, Krabbendam L, Radstake S, van Os J (in press) How psychotic are individuals with non-psychotic disorders? Soc Psychiatry Psychiatr EpidemiolGoogle Scholar
- 19.Krabbendam L, Myin-Germeys I, de Graaf R, Vollebergh W, Nolen WA, van Os J (in press) Dimensions of depression, mania, and psychosis in the general population. Psychol MedGoogle Scholar
- 20.Kraepelin E (1971) Dementia Præcox and Paraphrenia. Robert E Krieger Publishing, New YorkGoogle Scholar
- 23.Liddle PF, Barnes TR, Morris D, Haque S (1989) Three syndromes in chronic schizophrenia. Br J Psychiatry Suppl:119–122Google Scholar
- 26.Minas IH, Klimidis S, Stuart GW, Copolov DL, Singh BS (1994) Positive and negative symptoms in the psychoses: principal components analysis of items from the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms. Compr Psychiatry 35:135–144CrossRefPubMedGoogle Scholar
- 34.Smeets RMW, Dingemans PMAJ (1993) Composite International Diagnostic Interview (CIDI) Version 1.1. World Health Organization, Amsterdam/GenevaGoogle Scholar
- 37.Strauss JS, Carpenter WT Jr, Bartko JJ (1974) The diagnosis and understanding of schizophrenia. Part III. Speculations on the processes that underlie schizophrenic symptoms and signs. Schizophr Bull pp. 61–69Google Scholar
- 43.van Os J, Verdoux H, Bijl RV, Ravelli A (1999a) Psychosis as an extreme of continuous variation in dimensions of psychopathology. Search for the Causes of Schizophrenia. Gattaz WF, Hafner H, Steinkopff, Darmstadt vol. 4:59–79Google Scholar
- 47.WHO (1990) Composite International Diagnostic Interview (CIDI); Version 1.0. GenevaGoogle Scholar