Skip to main content
×
Home
    • Aa
    • Aa

Why we need more debate on whether psychotic symptoms lie on a continuum with normality

  • A. S. David (a1)
Abstract

The notion that psychotic symptoms lie on a continuum with normality has become an accepted dogma. It is supported by several lines of empirical evidence, fits in with the orientation of modern services and has a ‘moral’ appeal. However, there is confusion as to the nature of the continuum or continua under discussion. According to the author, commentators on this topic do not often distinguish between the variability and severity of the phenomena themselves, within or between individuals, versus the distribution of symptoms or risk factors in a population. The implications of these two types of continua differ. Furthermore, the evidence for continua of delusional beliefs and hallucinations can be challenged on a number of grounds, both methodological and conceptual. To some extent, whether phenomena are viewed as continua or categories depends on the intentions of the observer. Finding the distinctive characteristics of psychotic phenomena in people with clinical disorders, in addition to their origins in ‘normal’ cognitive processes, is a worthwhile goal.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Why we need more debate on whether psychotic symptoms lie on a continuum with normality
      Available formats
      ×
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about sending content to Dropbox.

      Why we need more debate on whether psychotic symptoms lie on a continuum with normality
      Available formats
      ×
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about sending content to Google Drive.

      Why we need more debate on whether psychotic symptoms lie on a continuum with normality
      Available formats
      ×
Copyright
Corresponding author
*Address for correspondence: A. S. David, M.D., FRCP, FRCPsych., M.Sc., Section of Cognitive Neuropsychiatry, PO Box 68, Institute of Psychiatry, King's College, Denmark Hill, London SE5 8AF, UK. (Email: anthony.david@kcl.ac.uk)
References
Hide All
Bentall RP (2003). Madness Explained: Psychosis and Human Nature. Penguin Books Ltd: London.
Charlton BG (1995). A critique of Geoffrey Rose's ‘population strategy’ for preventive medicine. Journal of the Royal Society of Medicine 88, 607610.
Claridge GA (1994). A single indicator of risk for schizophrenia. Probable fact or likely myth? Schizophrenia Bulletin 20, 151168.
Daalman K, Boks MPM, Diederen KMJ, de Weijer AD, Blom JD, Kahn RS, Sommer IEC (in press). Same or different auditory verbal hallucinations in healthy and psychotic individuals. Journal of Clinical Psychiatry.
David AS (1993). Cognitive neuropsychiatry? Psychological Medicine 23, 15.
David AS (1999). On the impossibility of defining delusions. Philosophy, Psychiatry, and Psychology 6, 1720.
Everitt BS, Landau S, Leese M (eds) (2001). Cluster Analysis, 4th edn. Arnold: London.
Freeman D (2007). Suspicious minds: the psychology of persecutory delusions. Clinical Psychological Review 27, 425457.
Garety PA, Hemsley DR (1987). Characteristics of delusional experience. European Archives of Psychiatry and Clinical Neuroscience 236, 294298.
Horwood J, Salvi G, Thomas K, Duffy L, Gunnell D, Hollis C, Lewis G, Menezes P, Thompson A, Wolke D, Zammit S, Harrison G (2008). IQ and non-clinical psychotic symptoms in 12-year-olds: results from the ALSPAC birth cohort. British Journal of Psychiatry 193, 185191.
Johns LC, van Os J (2001). The continuity of psychotic experiences in the general population. Clinical Psychology Review 21, 11251141.
Kessler RC (2002). The categorical versus dimensional assessment controversy in the sociology of mental illness. Journal of Health and Social Behavior 43, 171188.
Kretschmer E (1925). Physique and Character, pp. 118119. Kegan Paul, Trench, Trubner: London, UK.
Laurens KR, Hodgins S, Maughan B, Murray RM, Rutter ML, Taylor EA (2007). Community screening for psychotic-like experiences and other putative antecedents of schizophrenia in children aged 9–12 years. Schizophrenia Research 90, 130146.
Lincoln TM (2007). Relevant dimensions of delusions: continuing the continuum versus category debate. Schizophrenia Research 93, 211220.
Lincoln TM, Keller E (2008). Delusions and hallucinations in students compared to the general population. Psychology and Psychotherapy 81, 231235.
Linscott RJ, van Os J (2010). Systematic reviews of categorical and continuum models of psychosis: evidence for discontinuous subpopulations underlying a psychometric continuum. Implications for DSM-V, DSM-VI and DSM-VII. Annual Review of Clinical Psychology 6, 14.114.29.
McGorry PD (2005). Early intervention in psychotic disorders: beyond debate to solving problems. British Journal of Psychiatry 187, s108s110.
Meehl PE (1962). Schizotaxia, schizotypy, schizophrenia. American Psychology 17, 827838.
Mojtabai R, Malaspina D, Susser E (2003). The concept of population prevention: application to schizophrenia. Schizophrenia Bulletin 29, 791801.
Mullen R (2003). Delusions: the continuum versus category debate. Australia and New Zealand Journal of Psychiatry 37, 505511.
Nayani T, David AS (1996). The auditory hallucination: a phenomenological survey. Psychological Medicine 26, 177189.
Peters ER, Joseph SA, Day S, Garety PA (2004). Measuring delusional ideation: the 21-item Peters et al. Delusions Inventory (PDI). Schizophrenia Bulletin 30, 10051022.
Peters ER, Joseph SA, Garety PA (1999). Measurement of delusional ideation in the normal population: introducing the PDI (Peters et al. Delusions Inventory). Schizophrenia Bulletin 25, 553576.
Poulton R, Caspi A, Moffitt TE, Cannon M, Murray R, Harrington HL (2000). Children's self-reported psychotic symptoms and adult schizophreniform disorder: a 15-year longitudinal study. Archives of General Psychiatry 57, 10531058.
Read J, Harre N (2001). The role of biological and genetic causal beliefs in the stigmatisation of ‘mental patients’. Journal of Mental Health 10, 223235.
Rose G (1992). The Strategy of Preventive Medicine. Oxford University Press: Oxford.
Simon AE, Cattapan-Ludewig K, Gruber K, Ouertani J, Zimmer A, Roth B, Isler E, Umbricht D (2009). Subclinical hallucinations in adolescent outpatients: an outcome study. Schizophrenia Research 108, 265271.
Sommer IEC, Daalman K, Rietkerk T, Diederen KM, Bakker S, Wijkstra J, Boks MPM (2008). Healthy individuals with auditory verbal hallucinations: who are they? Psychiatric assessments of a selected sample of 103 subjects. Schizophrenia Bulletin. Published online: 9 October 2008. doi:10.1093/schbul/sbn130.
Stanton B, David AS (2000). First person accounts of delusions. Psychiatric Bulletin 24, 333336.
Stip E, Letourneau G (2009). Psychotic symptoms as a continuum between normality and pathology. Canadian Journal of Psychiatry 54, 140151.
Strauss JS (1969). Hallucinations and delusions as points on continua function. Archive of General Psychiatry 21, 581586.
van Os J, Hanssen M, Bijl RV, Ravelli A (2000). Strauss (1969) revisited: a psychosis continuum in the general population? Schizophrenia Research 45, 1120.
van Os J, Linscott RJ, Myin-Germeys I, Delespaul P, Krabbendam L (2009). A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness-persistence-impairment model of psychotic disorder. Psychological Medicine 39, 179195.
Verdoux H, Maurice-Tison S, Gay B, van Os J, Salamon R, Bourgeois ML (1998). A survey of delusional ideation in primary-care patients. Psychological Medicine 28, 127134.
Verdoux H, van Os J (2002). Psychotic symptoms in non-clinical populations and the continuum of psychosis. Schizophrenia Research 54, 5965.
Yung AR, Phillips LJ, Yuen HP, Francey SM, McFarlane CA, Hallgren M, McGorry PD (2003). Psychosis prediction: 12-month follow up of a high-risk (‘prodromal’) group. Schizophrenia Research 60, 2132.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Psychological Medicine
  • ISSN: 0033-2917
  • EISSN: 1469-8978
  • URL: /core/journals/psychological-medicine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords:

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 38
Total number of PDF views: 250 *
Loading metrics...

Abstract views

Total abstract views: 363 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 24th October 2017. This data will be updated every 24 hours.