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Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia
Version 1
: Received: 9 July 2019 / Approved: 10 July 2019 / Online: 10 July 2019 (11:02:41 CEST)
How to cite:
Almulla, A.; Al-Hakeim, H.; Maes, M. Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia. Preprints2019, 2019070147. https://doi.org/10.20944/preprints201907.0147.v1
Almulla, A.; Al-Hakeim, H.; Maes, M. Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia. Preprints 2019, 2019070147. https://doi.org/10.20944/preprints201907.0147.v1
Almulla, A.; Al-Hakeim, H.; Maes, M. Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia. Preprints2019, 2019070147. https://doi.org/10.20944/preprints201907.0147.v1
APA Style
Almulla, A., Al-Hakeim, H., & Maes, M. (2019). Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia. Preprints. https://doi.org/10.20944/preprints201907.0147.v1
Chicago/Turabian Style
Almulla, A., Hussein Al-Hakeim and Michael Maes. 2019 "Schizophrenia Phenomenology Revisited: Positive and Negative Symptoms are Strongly Related Reflective Manifestations of an Underlying Single Trait Indicating Overall Severity of Schizophrenia" Preprints. https://doi.org/10.20944/preprints201907.0147.v1
Abstract
Schizophrenia comprises various symptom domains, including positive and negative symptoms. Machine learning showed that a) negative symptoms are significantly interrelated with PHEM (psychosis, hostility, excitation, and mannerism) symptoms, formal thought disorders (FTD) and psychomotor retardation (PMR); and b) stable phase schizophrenia comprises two distinct classes, namely Major Neuro-Cognitive Psychosis (MNP, largely overlapping with deficit schizophrenia) and Simple NP (SNP). In this study, we recruited 120 MNP patients and 54 healthy subjects and measured the above-mentioned symptom domains. In MNP, there were significant associations between negative and PHEM symptoms, FTD and PMR. A single latent trait, which is essentially unidimensional, underlies these key domains of schizophrenia and MNP and additionally shows excellent internal consistency reliability, convergent validity, and predictive relevance. Confirmatory Tedrad Analysis indicates that this latent vector fits a reflective model. The lack of discriminant validity shows that PHEM and negative symptoms greatly overlap and probably measure the same construct. Soft Independent Modeling of Class Analogy (SIMCA) shows that MNP (diagnosis based on negative symptoms) is better modeled using PHEM symptoms, FTD, and PMR than negative symptoms. In conclusion, in stable phase MNP, a restricted sample of the schizophrenia population, negative and PHEM symptoms, FTD and PMR belong to one underlying latent vector reflecting overall severity of schizophrenia (OSOS). The bi-dimensional concept of “positive” and “negative” symptoms cannot be validated and, therefore, future research in stable phase schizophrenia should consider that the latent phenomenon OSOS as well as its 8 reflective manifestations are the key factors of schizophrenia phenomenology.
Medicine and Pharmacology, Psychiatry and Mental Health
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
