Symptômes Positifs Et Négatifs De La Schizophrénie: Une Mise à jour

1994 ◽  
Vol 39 (7) ◽  
pp. 407-414 ◽  
Author(s):  
Marc-André Roy ◽  
Xavier Devriendt

The purpose of this article is to summarize the results of studies examining the validity of the positive and negative sub-types of schizophrenia as proposed by Crow. The authors summarized Crow's model's predictions in the form of 12 research questions and examined whether its predictions were confirmed. The following predictions are generally confirmed by the data collected: (i) it is possible to measure negative symptoms with accuracy; (ii) the negative symptoms predict a deterioration; (Hi) the negative symptoms are generally correlated with overall cognitive deficits; (iv) each dimension appears to have distinct neurobiological substrata. However, several elements of the Crow model are not supported by the data collected. Among the necessary modifications, the most important are as follows: (i) it appears more productive to conceive of the negative symptoms as distinct dimensions, rather than distinct diseases; (ii) at least three dimensions exist for describing the symptoms of schizophrenia; (Hi) the negative symptoms are not necessarily intrinsic to the schizophrenic process, and they may be due to other causes; (iv) the negative symptoms are not necessarily irreversible, and can be improved under ataractics; (v) the positive symptoms, in particular those relating to disorganization, can also be correlated with cognitive deficits.

CNS Spectrums ◽  
2004 ◽  
Vol 9 (S9) ◽  
pp. 19-23 ◽  
Author(s):  
Alexander L. Miller

ABSTRACTCombination treatments, especially combinations of antipsychotics, are used frequently for schizophrenia, despite a paucity of evidence regarding their safety and efficacy. Because the literature basis is weak and expert recommendations are largely lacking, providers should be vigilant in documenting improved outcomes for patients thought to benefit from combination treatments. Target symptoms that have been studied include psychosis, cognitive deficits, and negative symptoms. The strongest evidence is for augmentation of clozapine with another antipsychotic or with electroconvulsive therapy for persistent positive symptoms. Combination treatments for cognitive deficits and negative symptoms are being actively investigated, but current evidence is insufficient to recommend available agents for these components of schizophrenia. It is important that appropriate monotherapies be given adequate trials before resorting to combination therapies.


Author(s):  
Nancy C Andreasen

Schizophrenia is a devastating illness that usually affects many aspects of a person’s life. The symptoms may be divided into two groups. ‘Positive’ symptoms include a variety of psychotic symptoms such as delusions and hallucinations. Although severe, they are less handicapping than negative symptoms such as avolition or anhedonia. Positive symptoms involve the presence of things that should be absent, while negative symptoms involve the absence of things that should be present. Dimensional approaches for classifying symptoms have also become popular in current nosology, proposing three dimensions: positive, negative, and disorganized. The course of the illness evolves over time; a prodrome is often present, followed by illness onset and a variable outcome. Good outcome predictors include good premorbid adjustment, high intelligence quotient, and good social relationships. The pathophysiology of the illness includes genetic, neuropathological, and neurodevelopmental components. A possible association with creativity may suggest reasons why the illness has persisted over many centuries.


1997 ◽  
Vol 9 (2) ◽  
pp. 64-67
Author(s):  
R.S. Kahn

The dopamine (DA) hypothesis of schizophrenia, postulating that schizophrenia is characterized by increased dopamine function, has been the most influential theory on the pathogenesis of schizophrenia. It has recently been revised based on the appreciation that the core symptoms of schizophrenia may not be the positive (psychotic) symptoms, but rather the negative symptoms and the cognitive deficits found in schizophrenic patients. This revision has prompted the hypothesis that schizophrenia is characterized by both decreased prefrontal dopamine activity (causing deficit symptoms) and increased dopamine activity in mesolimbic dopamine neurons (causing positive symptoms).Notwithstanding this revision of a role for dopamine in schizophrenia, it has become increasingly evident that dysfunction of other monoaminergic systems may be as important in contributing to the pathophysiology of schizophrenia. Specifically, the putative role of serotonin (5-hydroxytryptamine, 5-HT) in schizophrenia is gaining considerable attention. Several observations, such as the ability of the 5-HT antagonist, ritanserin, to alleviate schizophrenic symptoms and, when added to haloperidol (Haldol®), to decrease its extrapyramidal side-effects (EPS), have stimulated studies into a role of 5-HT in schizophrenia. The finding that clozapine (Leponex®), clinically superior to conventional neuroleptics, is a weak DA2 antagonist but a potent 5-HT1c and 5-HT2 antagonist has further stimulated 5-HT-related research in schizophrenia.


Author(s):  
James Gilleen

Schizophrenia is characterized by a constellation of heterogeneous symptoms including hallucinations and delusions, motivational and social deficits, and cognitive impairments. Although positive symptoms have historically been the target for drug development, in recent years, attention has turned to cognitive and negative symptoms. Cognitive deficits in schizophrenia are associated with significant impairments in functional, social, and employment outcomes, and although they are widely researched and relatively well understood, there are no currently approved compounds to treat them. This chapter provides a selective review of the current status of approaches developed to improve cognition in schizophrenia. It covers pharmacological approaches as well as cognitive training and cognitive remediation techniques. It also explores the various study design issues and challenges that contribute to the difficulties in discovering reliable ways to improve the cognitive deficits present in schizophrenia.


2013 ◽  
Vol 203 (3) ◽  
pp. 172-178 ◽  
Author(s):  
Kee-Hong Choi ◽  
Til Wykes ◽  
Matthew M. Kurtz

BackgroundA growing number of studies have investigated the efficacy of novel, adjunctive pharmacotherapies for treatment of cognitive deficits in schizophrenia with conflicting results.AimsTo investigate the comparative efficacy of these agents on cognition and symptoms in schizophrenia, and to identify promising cognitive domains and candidate medications that can be incorporated in treatment trials combined with cognitive remediation to maximise treatment effects.MethodA total of 26 double-blind, placebo-controlled studies investigating medications targeted at cholinergic, glutamatergic or serotonergic receptor classes and with participants with schizophrenia or schizoaffective disorder were identified.ResultsMedications targeted at the cholinergic receptor class produced marginal improvements in verbal learning and memory (d = 0.23, P = 0.06), and donepezil, a specific type of cholinergic agonist, produced a moderate effect (d = 0.58) on spatial learning and memory. Cholinergic and glutamatergic agents produced moderate effect-size improvements on negative symptoms (d = 0.54 and d = 0.62 respectively), and small effect-size improvements on general symptoms (d = 0.46 and d = 0.41 respectively). Serotonergic agents produced small effect-size improvements in positive symptoms (d = 0.33).ConclusionsCholinergic medications produced marginal improvement in verbal learning and memory and moderate improvements on spatial learning and memory, although there was no evidence to support the use of glutamatergic or serotonergic medications as a stand-alone treatment for improving cognitive function. Cholinergic and glutamatergic agents improved negative and general symptoms, whereas serotenergic medications improved positive symptoms.


1999 ◽  
Vol 174 (S38) ◽  
pp. 5-11 ◽  
Author(s):  
N. A. Moore

Antipsychotic agents have been the mainstay in the management of schizophrenia for a number of years. Their therapeutic efficacy is primarily attributed to dopamine receptor antagonism (Creese et al, 1976), leading to a reduction in the positive symptoms of schizophrenia such as paranoia and hallucinations. Unfortunately, they have little effect on the negative symptoms (such as flattened affect, poverty of speech, anhedonia and social withdrawal) or cognitive deficits. The blockade of central dopamine receptors by classical antipsychotic agents also leads to the development of both acute and chronic motor disturbances (extrapyramidal side-effects) (EPS) (Meltzer, 1992).


2008 ◽  
Vol 31 (4) ◽  
pp. 10
Author(s):  
G Foussias ◽  
G Remington ◽  
R Mizrahi

Background: Schizophreniais a chronic and debilitating illness that affects approximately one percent of the population. The symptoms of schizophrenia are typically thought of in separate domains, including positive symptoms (hallucinations and delusions), negative symptoms (diminished emotional expression and amotivation), and cognitive deficits. Importantly, the negative symptoms have been consistently found to adversely influence functional outcomes, in particular due to markedamotivation.^1 There have been suggestions that these individuals also experience deficits in the experience of pleasure, especially in their capacity to anticipate pleasure.^2 However, such investigations have not included the examination of these symptoms in those in the prodromal phase ofthis illness, a time that holds promise for early intervention and altering thecourse of schizophrenia.^3 Methods: In an effort to examine deficits in motivation and pleasure in the prodromal phase of schizophrenia, we have used an experience sampling method to assess “in the moment” motivation and pleasure in individuals at high risk of developing schizophrenia and healthy controls. Subjects completed baseline assessments including evaluation of their positive and negative symptoms. Subsequently, through the use of a personal digital assistant, subjects rated their motivation and experience of consummatory and anticipatory pleasure in their daily lives, multiple times over the course of four days. Results and Conclusions: Preliminary data will be presented, as well as the importance of these findings in the context of understanding the underlying pathobiology of this illness, and guiding our search for effective treatments to improvefunctional outcomes in schizophrenia. References: 1. Sayers SL, Curran PJ, Mueser KT. Psychol Assessment 1996;8:269-80. 2. Gard DE, Kring AM, Gard GM, et al.. Schizophr Res 2007;93:253-60.


2019 ◽  
Vol 47 (11) ◽  
pp. 1-8 ◽  
Author(s):  
AiBao Zhou ◽  
Pei Xie ◽  
ChaoChao Pan ◽  
Zhe Tian ◽  
Junwei Xie

We explored differences in performance on the Synthetic House–Tree–Person Test between people with mainly positive symptoms and those with mainly negative symptoms of schizophrenia and, further, aimed to provide a basis for the diagnosis of schizophrenia symptom type. Participants were 58 people receiving treatment for schizophrenia, and we asked them to complete the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Synthetic House–Tree–Person Test. There were significant differences in results on the Synthetic House–Tree–Person Test between the group with positive symptoms, the group with a mix of positive and negative symptoms, and the group with negative symptoms. There were 12 features of participants' drawings, such as big hands, which were correlated with hallucinations and delusions in positive symptoms, and 9 features, such as trees in a landscape, which were correlated with avolition and anhedonia in negative symptoms. Our study results suggest differences in performance on the Synthetic House–Tree–Person Test between these different symptom subtypes of schizophrenia; hence, the features that appear in drawings made during the test may contribute to the diagnosis of symptoms of people with schizophrenia.


1986 ◽  
Vol 1 (2) ◽  
pp. 108-122 ◽  
Author(s):  
Nancy C. Andreasen ◽  
William M. Grove

SummaryMost investigators concur that schizophrenia is probably a heterogeneous group of disorders that share the common features of psychotic symptoms, partial response to neuroleptics, and a relatively poor outcome. The subdivision of schizophrenia into two subtypes, positive versus negative, has achieved wide acceptance throughout the world during recent years. This distinction has heuristic and theoretical appeal because it unites phenomenology, pathophysiology, and etiology into a single comprehensive hypothesis.In spite of its wide appeal, the distinction has a number of problems. These include the failure to distinguish between symptom syndromes and diseases; failure to deal with the mixed patient; failure to take longitudinal course into account; and failure to address conceptually and methodologically the distinction between positive and negative symptoms.This paper focuses primarily on the conceptual basis for two instruments designed to measure positive and negative symptoms, the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS), originally described in 1982. Since their description, these scales have been used in a variety of other centers. These scales are based on the hypothesis that negative symptoms represent a deficit or diminution in normal psychological functions wliile positive symptoms represent an excess or distortion of normal functions. Reliability data are now available from Italy, Spain, and Japan which suggest that these scales can be used reliably in cultural settings outside the United States. The results of these studies are summarized in this paper. In addition, a replication study involving a new sample of 117 schizophrenics collected at the University of Iowa is described. In this second study of the SANS and SAPS, internal consistency is found to be quite high in the SANS. Thus negative symptoms appear to be more internally correlated with one another than are positive symptoms. The implications of this result are discussed. A principal components analysis is used to explore the relationship between positive and negative symptoms. While the study reported in 1982 suggested that positive and negative symptoms are negatively correlated, in the present study they appear to be uncorrelated. Overall, the results suggest that the SANS and SAPS are useful comprehensive instruments for the evaluation of positive and negative symptoms. The relationship between these symptoms and external validators such as cognitive functioning or CT scan abnormalities will be reported in a subsequent investigation.


2021 ◽  
Vol 13 (3) ◽  
pp. 343-358
Author(s):  
Hormazd D. Minwalla ◽  
Peter Wrzesinski ◽  
Allison Desforges ◽  
Joshua Caskey ◽  
Brittany Wagner ◽  
...  

Purpose of Review: This is a comprehensive review of the literature regarding the use of paliperidone in the treatment of schizophrenia and schizoaffective disorder. It covers the background and presentation of schizophrenia and schizoaffective disorder, as well as the mechanism of action and drug information for paliperidone. It covers the existing evidence of the use of paliperidone for the treatment of schizophrenia and schizoaffective disorder. Recent Findings: Schizophrenia and schizoaffective disorder lead to significant cognitive impairment. It is thought that dopamine dysregulation is the culprit for the positive symptoms of schizophrenia and schizoaffective disorder. Similar to other second-generation antipsychotics, paliperidone has affinity for dopamine D2 and serotonin 5-HT2A receptors. Paliperidone was granted approval in the United States in 2006 to be used in the treatment of schizophrenia and in 2009 for schizoaffective disorder. Summary: Schizophrenia and schizoaffective disorder have a large impact on cognitive impairment, positive symptoms and negative symptoms. Patients with either of these mental illnesses suffer from impairments in everyday life. Paliperidone has been shown to reduce symptoms of schizophrenia and schizoaffective disorder.


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