A Disappearing Heritage

The Clinical Core of Schizophrenia

Josef Parnas


Schizophr Bull. 2011;37(6):1121-1130. 

In This Article

Abstract and Introduction


This article traces the fundamental descriptive features of schizophrenia described in the European continental literature form Kraepelin and Bleuler, culminating with the creation of the International Classification of Diseases (ICD)-8 (1974). There was a consensus among the researchers that the specificity and typicality of schizophrenia was anchored to its "fundamental" clinical core (with trait status) and not to positive psychotic features, which were considered as "state", "accessory" phenomena. The clinical core of schizophrenia was, in a diluted form, constitutive of the spectrum conditions ("schizoidia" and "latent schizophrenia"). The fundamental features are manifest across all domains of consciousness: subjective experience, expression, cognition, affectivity, behavior, and willing. Yet, the specificity of the core was only graspable at a more comprehensive Gestalt-level, variously designated (eg, discordance, autism, "Spaltung"), and not on the level of single features. In other words, the phenomenological specificity was seen as being expressive of a fundamental structural or formal change of the patient's mentality (consciousness, subjectivity). This overall change transpires through the single symptoms and signs, lending them a characteristic phenomenological pattern. This concept of schizophrenia bears little resemblance to the current operational definitions. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and ICD-10 seem to diagnose a subset of patients with chronic paranoid-hallucinatory variant of schizophrenia.


The purpose of this contribution is to make a panoptic attempt to describe how schizophrenia was conceptualized in the continental European psychiatry and described since Bleuler and Kraepelin and as recently as in the 8th and 9th editions of the International Classification of Diseases (ICD) ie, in practical clinical use in Europe at least until the introduction of the ICD-10[1] in 1992.

The knowledge of the core features has gradually faded away in the operational permutations of the schizophrenia concept. This notion becomes increasingly alien to clinicians. This is partly due to a reification of diagnostic categories, associated with a general decline of psychopathological competence.[2]

A centenary of the publication of Bleuler's "Dementia Praecox or the Group of Schizophrenias" is a pretext for this reflection. The reader should not expect a historical exegesis of Bleuler's ideas. Rather, the goal will be to trace the evolution of the concept of the clinical core of schizophrenia into its common continental articulation in ICD-8,[3] before the creation of Diagnostic and Statistical Manual of Mental Disorders, Third Edition, (DSM-III).[4]

The preoperational notion of schizophrenia may be considered as a zenith of psychopathologic research, creating conditions for the first major scientific accomplishments, eg, the foundational Scandinavian epidemiological studies,[5] the US-DK Adoption studies,[6] the US-DK high-risk studies,[7] longitudinal patient follow-up studies,[8,9] and the WHO's International Pilot Studies of Schizophrenia.[10] The modifications of the concept of schizophrenia that happened in the DSM-III-DSM-IV-TR[4,11] and the ICD-10 entail obvious and important clinical and research consequences.