Schizophrenia, “just the facts” 4. Clinical features and conceptualization

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Abstract

Although dementia praecox or schizophrenia has been considered a unique disease entity for the past century, its definitions and boundaries have continued to vary over this period. At any given time, the changing concept of schizophrenia has been influenced by available diagnostic tools and treatments, related conditions from which it most needs to be distinguished, extant knowledge and scientific paradigms. There is significant heterogeneity in the etiopathology, symptomatology, and course of schizophrenia. It is characterized by an admixture of positive, negative, cognitive, mood, and motor symptoms whose severity varies across patients and through the course of the illness. Positive symptoms usually first begin in adolescence or early adulthood, but are often preceded by varying degrees of negative and cognitive symptomatology. Schizophrenia tends to be a chronic and relapsing disorder with generally incomplete remissions, variable degrees of functional impairment and social disability, frequent comorbid substance abuse, and decreased longevity. Although schizophrenia may not represent a single disease with a unitary etiology or pathogenetic process, alternative approaches have thus far been unsuccessful in better defining this syndrome or its component entities. The symptomatologic, course, and etio-pathological heterogeneity can usefully be addressed by a dimensional approach to psychopathology, a clinical staging approach to illness course, and by elucidating endophenotypes and markers of illness progression, respectively. This will allow an approach to the deconstruction of schizophrenia into its multiple component parts and strategies to reconfigure these components in a more meaningful manner. Possible implications for DSM-V and ICD-11 definitions of schizophrenia are discussed.

Introduction

Although schizophrenia has been extensively studied and described as a disease entity for the past century, its precise clinical nature remains undefined. Since its demarcation and labeling as dementia praecox by Kraepelin (1919) and schizophrenia by Eugen Bleuler (1911), both its definitions and scope have varied (Nasrallah and Smelzer, 2003). It has been suggested that changing definitions of schizophrenia impede research into its nature as investigators keep chasing a moving target. Conversely, it has been argued that only a better understanding of schizophrenia can lead to its more precise definition. We have previously summarized a series of replicable and durable “facts” in schizophrenia (Tandon et al., 2008a). In this article, we elaborate the core clinical features of schizophrenia (Table 1) and discuss its diagnostic criteria. Since definition of a disorder and description of its nature are two aspects of an iterative process, we begin with a discussion of its evolving definitions leading up to current diagnostic criteria.

Section snippets

Evolution of the concept of schizophrenia from Kraepelin to DSM-IV-TR (Fig. 1)

Our present conceptualization of dementia praecox and schizophrenia derives principally from the work of Kraepelin (1919), Bleuler (1911) and Schneider (1959); differences in their ideas about the basic nature of this illness have caused discrepancies in its definition over the past century (Hoenig, 1983). Although case descriptions resembling schizophrenia go back a few millennia, its consideration as a disease entity dates back to the mid-19th century. Griesinger (1861) described what would

Clinical features of schizophrenia

Although there is no consensus about the essential criteria that must be met to make a definite diagnosis of schizophrenia, there is broad agreement about the general clinical features of the schizophrenic syndrome. Table 1 summarizes what we currently believe about the clinical expression of schizophrenia with varying degrees of confidence. We briefly discuss each of these clinical features [psychopathology, outcome, and course] and then explore its varied expression (heterogeneity).

Reconceptualizing schizophrenia

The authors propose that while it is premature to dump the very concept of schizophrenia, it is necessary to discard the current construct, disassemble its components, and reconstruct a more valid and meaningful entity.

Given the extreme heterogeneity across its clinical expression, as also its etiology and pathophysiology as discussed in previously published articles in this series (Keshavan et al., 2008; Tandon et al., 2008b), some have suggested that it is time to completely abandon the

In conclusion

The clinical characterization of schizophrenia is marked by several paradoxes. It is very unlikely to be a unitary disease entity and yet it appears to be one of the best validated psychiatric diagnoses. Despite the absence of pathognomonic clinical features or specific laboratory tests, it has high inter-rater diagnostic reliability and universally accepted broad prognostic and treatment implications. We know enough about the present construct of schizophrenia to recognize that it may be a

Role of funding source

Independently prepared by authors. No external funding.

Contributors

Contributors to research and writing of manuscript. Rajiv Tandon, Henry Nasrallah, and Matcheri Keshavan.

Conflict of interest

This statement was independently developed by Rajiv Tandon, Matcheri S. Keshavan, and Henry A. Nasrallah.

Acknowledgements

We acknowledge the tens of thousands of patients who have taught us what really matters in schizophrenia and our clinical and research colleagues who continually help us sharpen our thinking about its essential nature.

References (432)

  • CannonM. et al.

    Risk for schizophrenia-broadening the concepts, pushing back the boundaries

    Schizophr. Res.

    (2005)
  • CannonT.D.

    Neurodevelopment and the transition from schizophrenia prodrome to schizophrenia: research imperatives

    Biol. Psychiatry

    (2008)
  • CapassoR.M. et al.

    Mortality in schizophrenia and schizoaffective disorder: an Olmstead County, Minnesota cohort: 1950–2005

    Schizophr. Res.

    (2008)
  • CarpenterW.T.

    Clinical constructs and therapeutic discovery

    Schizophr. Res.

    (2004)
  • CarrollA. et al.

    Correlates of insight and insight change in schizophrenia

    Schizophr. Res.

    (1999)
  • ChanR.C. et al.

    Neurological soft signs as candidate endophenotypes for schizophrenia: a shooting star or a Northern star?

    Neurosci. Biobehav. Rev.

    (2008)
  • CheniauxE. et al.

    Does schizoaffective disorder really exist? A systematic review of the studies that compared schizoaffective disorder with schizophrenia or mood disorders

    J. Affect. Disord.

    (2008)
  • ComptonM.T.

    Considering schizophrenia from a prevention perspective

    Am. J. Prev. Med.

    (2004)
  • ComptonM.T. et al.

    Neurological soft signs and minor physical anomalies in patients with schizophrenia and related disorders, their first-degree biological relatives, and non-psychiatric controls

    Schizophr. Res.

    (2007)
  • ConleyR.R. et al.

    The burden of depressive symptoms in the long-term treatment of patients with schizophrenia

    Schizophr. Res.

    (2007)
  • DeanK. et al.

    Minor physical anomalies across ethnic groups in a first-episode psychosis sample

    Schizophr. Res.

    (2007)
  • de LeonJ. et al.

    A meta-analysis of worldwide studies demonstrates an association between schizophrenia and tobacco smoking behaviors

    Schizophr. Res.

    (2005)
  • DevulapalliK.K. et al.

    Temporal sequence of clinical manifestation in schizophrenia with co-morbid OCD: review and meta-analysis

    Psychiatr. Res.

    (2008)
  • DickinsonD. et al.

    General and specific cognitive deficits in schizophrenia: Goliath defeats David

    Biol. Psychiatry.

    (2008)
  • AchimA.M. et al.

    Episodic memory-related activation in schizophrenia: meta-analysis

    Br. J. Psychiatry

    (2005)
  • AddingtonJ. et al.

    North American Prodrome Longitudinal Study: a collaborative multisite approach to prodromal schizophrenia research

    Schizophr. Bull.

    (2007)
  • AlemanA. et al.

    Insight in psychosis and neuropsychological function: meta-analysis

    Br. J. Psychiatry

    (2006)
  • AlemanA. et al.

    Memory impairment in schizophrenia: a meta-analysis

    Am. J. Psychiatry

    (1999)
  • Allen, A.J., Griss, M.E., Folley, B.S., et al., Endophenotypes in schizophrenia: a selective review. Schizophr....
  • AlvesT.M. et al.

    The psychopathological factors of refractory schizophrenia

    Rev. Bras. Psiquiatr.

    (2005)
  • American Psychiatric Association

    Diagnostic and Statistical Manual of Mental Disorders

    (1968)
  • American Psychiatric Association

    Diagnostic and Statistical Manual of Mental Disorders

    (1980)
  • American Psychiatric Association

    Diagnostic and Statistical Manual of Mental Disorders

    (2000)
  • AndreasenN.C.

    Thought, language, and communication disorders: I. Clinical assessment, definition of terms, and evaluation of their reliability

    Arch. Gen. Psychiatry

    (1979)
  • AndreasenN.C.

    Negative symptoms in schizophrenia. Definition and reliability

    Arch. Gen. Psychiatry

    (1982)
  • AndreasenN.C.

    DSM and the death of phenomenology in America: an example of unintended consequences

    Schizophr. Bull.

    (2007)
  • AndreasenN.C. et al.

    Remission in schizophrenia: proposed criteria and rationale for consensus

    Am. J. Psychiatry

    (2005)
  • Androutsellis-TheotokisA. et al.

    Notch signaling regulates stem cell numbers in vitro and in vivo

    Nature

    (2006)
  • AngermeyerM.C. et al.

    Gender differences in age at onset of schizophrenia. An overview

    Eur. Arch. Psychiatry Neurol. Sci.

    (1988)
  • ArnoldS.E. et al.

    Dysregulation of olfactory receptor neuron lineage in schizophrenia

    Arch. Gen. Psychiatry

    (2001)
  • AuquierP. et al.

    Mortality in schizophrenia

    Pharmacoepidemiol. Drug Saf.

    (2007)
  • AylwardE. et al.

    Intelligence in schizophrenia: meta-analysis of the research

    Schizophr. Bull.

    (1984)
  • Baca-GarciaE. et al.

    Diagnostic stability of psychiatric disorders in clinical practice

    Br. J. Psychiatry

    (2007)
  • BarakY. et al.

    Reduced cancer incidence among patients with schizophrenia

    Cancer

    (2005)
  • BarchD.M. et al.

    Context-processing deficits in schizophrenia: diagnostic specificity, 4-week course, and relationships to clinical symptoms

    J. Abnorm. Psychology

    (2003)
  • BeiserM. et al.

    Establishing the onset of psychotic illness

    Am. J. Psychiatry

    (1993)
  • BellR.C. et al.

    The dimensionality of schizophrenia concepts in first-episode psychosis

    Acta Psychiatr. Scand.

    (1998)
  • BentallR.P. et al.

    Abandoning the concept of ‘schizophrenia’

    Br. J. Clin. Psychol.

    (1988)
  • BermanzohnP.C. et al.

    Hierarchical diagnosis in chronic schizophrenia: a clinical study of co-occurring syndromes

    Schizophr. Bull.

    (2000)
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