Bereitschaftpotential in schizophrenia

1997 ◽  
Vol 171 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Taha Karaman ◽  
Sibel Özkaynak ◽  
Korkut Yaltkaya ◽  
Çetin Büyükberker
Keyword(s):  
Frontal Cortex ◽  
Negative Symptoms ◽  
Symptom Clusters ◽  
Positive Symptoms ◽  
Voluntary Movements ◽  
Healthy Controls ◽  
Late Component ◽  
Subcortical Structures ◽  
Schizophrenic Patients ◽  
Motor Abnormalities

BackgroundSeveral reports have documented the presence of motor abnormalities in schizophrenic patients.MethodThirty schizophrenics and 28 healthy controls were included in the study. Scalp-recorded bereitschaftpotentials (BPs) generated prior to voluntary movements were recorded in all subjects.ResultsThe early (NSI) and late components of BP and peak negativity were reduced in all schizophrenic patients. In particular, the NSI was reduced in patients with positive symptoms, and the late component in patients with negative symptoms.ConclusionsThese findings provide further support for the involvement of frontal cortex, subcortical structures and their connections in schizophrenia, and highlight some differences between positive and negative symptom clusters.

Cognitive Function in Schizophrenia: Association with Negative and Positive Symptoms

1996 ◽  
Vol 78 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Ronald A. Capleton
Keyword(s):  
Cognitive Functioning ◽  
Negative Symptoms ◽  
Wisconsin Card Sort Test ◽  
Positive Symptoms ◽  
Word Fluency ◽  
Generation Task ◽  
Card Sort ◽  
Word Generation ◽  
Perseverative Errors ◽  
Schizophrenic Patients

20 schizophrenic patients were classified as having either predominantly negative ( n = 11) or predominantly positive symptoms ( n = 9), utilizing the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms. Cognitive functioning was evaluated in these participants and 10 non-patient controls using a word-fluency test and word-generation task. Finally, all participants were evaluated using the Coglab Card Sort Test, a computerized version of the Wisconsin Card Sort Test. The only reliable difference in performance among groups was on perseverative errors on the Coglab Card Sort Test Schizophrenic participants made significantly more perseverative errors than controls and those classified as having primarily negative symptoms made more perseverative errors than those classified as having predominantly positive symptoms. These findings confirm previous reports with respect to cognitive functioning of schizophrenic patients and are consistent with the hypotheses regarding frontal lobe dysfunction in schizophrenia. These data encourage research with larger samples.

Negative Symptoms at Discharge and Outcome in Schizophrenia

1995 ◽  
Vol 166 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Hai-Gwo Hwu ◽  
Happy Tan ◽  
Chu-Chang Chen ◽  
Ling-Ling Yeh
Keyword(s):  
Clinical Outcome ◽  
Social Functioning ◽  
Symptom Score ◽  
Negative Symptoms ◽  
Positive Symptom ◽  
Positive Symptoms ◽  
Symptom Scores ◽  
Schizophrenic Patients ◽  
Positive And Negative Symptoms

BackgroundThe clinical significance in schizophrenia of positive and negative symptoms at discharge was assessed.MethodOf schizophrenic patients fulfilling DSM–III criteria, 113 were recruited for this study. Personal, social and psychopathological data were collected and all cases were followed up at one and two years after discharge.ResultsThe presence of positive symptoms (64 cases), without concomitant negative symptoms, did not predict the follow-up social function and positive symptom score. Conversely, the presence of negative symptoms (31 cases) predicted worse social functioning (P < 0.05 to P < 0.005) and higher positive symptom scores (P < 0.01) at follow-up using MANOVA. Eighteen cases (15.9%) had neither positive nor negative symptoms and had the best clinical outcome.ConclusionsNegative, but not positive, symptoms assessed at discharge are an important predictor of poor outcome. In addition, negative symptoms may themselves expose a biological vulnerability to the presence of positive symptoms.

scholarly journals O5.1. STRIATAL DOPAMINE AND REDUCED REWARD PREDICTION ERROR SIGNALING IN UNMEDICATED SCHIZOPHRENIA PATIENTS

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S11-S11
Author(s):  
Teresa Katthagen ◽  
Jakob Kaminski ◽  
Andreas Heinz ◽  
Ralph Buchert ◽  
Florian Schlagenhauf
Keyword(s):  
Prediction Error ◽  
Negative Symptoms ◽  
Ventral Striatum ◽  
Striatal Dopamine ◽  
Dopamine Synthesis ◽  
Positive Symptoms ◽  
Healthy Controls ◽  
Reward Prediction Error ◽  
Reward Prediction ◽  
Significant Difference

Abstract Background Increased striatal dopamine synthesis capacity (DSC) has consistently been reported in patients with schizophrenia (Sz). However, the functional mechanism translating this into behavior and symptoms remains unclear. It has been proposed that heightened striatal dopamine may blunt dopaminergic reward prediction error (RPE) signaling during reinforcement learning. Methods In this study, we investigated striatal DSC and RPEs and their association in unmedicated Sz and healthy controls. 23 healthy controls (HC) and 20 unmedicated Sz took part in an FDOPA-PET scan measuring DSC and underwent fMRI scanning, where they performed a reversal learning paradigm. We compared groups regarding DSC und neural RPE signals and probed the respective correlation (23 HC and 16 Sz for both measures). Results There was no significant difference between HC and Sz in DSC. Taking into account comorbid alcohol abuse revealed that only patients without such abuse showed elevated DSC in the associative and sensorimotor striatum, while those with abuse did not differ from HC. Patients performed worse during learning, accompanied by a reduced RPE signal in the ventral striatum. In HC, the DSC in the limbic striatum correlated with higher RPE signaling, while there was no significant association in patients. DSC in the associative striatum correlated with higher positive symptoms, and blunted RPE signaling was associated with negative symptoms. Discussion Our results suggest that dopamine modulation of RPE is impaired in schizophrenia. Furthermore, we observed a dissociation with elevated DSC in the associative and sensorimotor striatum contributing to positive symptoms and blunted RPE in the ventral striatum to negative symptoms.

New dopaminergic and non-dopaminergic theories in schizophrenia and their therapeutic impact

1997 ◽  
Vol 9 (2) ◽  
pp. 64-67
Author(s):  
R.S. Kahn
Keyword(s):  
Cognitive Deficits ◽  
Negative Symptoms ◽  
Dopamine Neurons ◽  
Psychotic Symptoms ◽  
Positive Symptoms ◽  
The Core ◽  
Schizophrenic Patients ◽  
Core Symptoms ◽  
Influential Theory

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.

Positive and Negative Symptoms in Psychiatry

1986 ◽  
Vol 148 (5) ◽  
pp. 587-589 ◽  
Author(s):  
Michael R. Trimble
Keyword(s):  
Negative Symptoms ◽  
Geographical Location ◽  
Personal Communication ◽  
Thought Disorder ◽  
Positive Symptom ◽  
Positive Symptoms ◽  
Market Research Company ◽  
Research Company ◽  
Schizophrenic Patients ◽  
Positive And Negative Symptoms

The terms positive and negative symptoms have slipped into the language of contemporary psychiatry with comparative ease. It is not uncommon for these expressions to be used with little explanation, both at meeting and in written communications, with the implicit understanding that their meaning is understood and that somehow they are of value to our knowledge of psychopathology. However, that there are no clear guide-lines at present for our use of these terms is shown from a recent survey of psychiatrists' opinions from a market research company (Martin Hamblin Research-Personal Communication). As part of a series of questions asked to many psychiatrists of differing age, geographical location, and status, they were asked about the meaning of these terms, positive and negative symptoms and the proportion of schizophrenic patients having them. Of the categories quoted by Crow (1980–81) as positive symptoms, 68% considered that delusions were positive symptoms, 63% hallucinations, and only 35% thought disorder. In contrast, 18% thought that behaviour disturbance was a positive symptom, a similar figure (15%) being given for passivity feelings. Considerable variation was noted, however, with hallucinations being considered positive by only 33% of London psychiatrists, thought disorder by only 11% of those qualified 16–25 years, and one-quarter of all registrars and psychiatrists from Midland Health Districts considered passivity feelings to fall into this category. Even greater disagreement was recorded for negative symptoms. Thus, the symptom most often associated with this category was apathy, by 52% of respondents. Only 26% considered that withdrawal was a negative symptom, the percentage data for lack of motivation and blunting of affect being 37% and 15% respectively.

Family History of Schizophrenia and the Relationship of Stress to Symptoms: Preliminary Findings

2001 ◽  
Vol 35 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Ross M. G. Norman ◽  
Ashok K. Malla
Keyword(s):  
Family History ◽  
Negative Affect ◽  
Negative Symptoms ◽  
Positive Family History ◽  
Positive Symptoms ◽  
Daily Stressors ◽  
Schizophrenic Patients ◽  
History Of ◽  
Relationship Of ◽  
The Relationship

Objective: It has been hypothesized that patients with a diagnosis of schizophrenia who have a positive family history for schizophrenia will show greater reactivity of their symptoms to increasing levels of stress or negative affect than will patients without such a family history. In the past this hypothesis has only been tested through manipulations of negative affect in laboratory settings. In this paper we test this hypothesis using longitudinal clinical data. Method: Data were derived from an earlier longitudinal study using monthly assessments of daily stressors (Hassles Scale) and symptom measures (the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms). We compared longitudinal stress to symptom relations in 12 patients with schizophrenia for whom a positive family history of schizophrenia could be identified with 12 matched schizophrenic patients without any known family history of psychiatric illness. Results: There was evidence that patients with a family history of schizophrenia demonstrated a stronger relation between stress and total score on the Scale for the Assessment of Positive Symptoms. This difference appears to have primarily reflected a greater reactivity to stress of reality distortion symptoms in the positive family history group. The two groups did not differ in apparent reactivity to stress of the disorganization and psychomotor poverty dimensions of symptomatology. Conclusions: The results of this study provide support from a naturalistic, longitudinal clinical study for the hypothesis that reactivity to stress of some symptoms of schizophrenia may vary as a function of family history of the disorder.

Tardive Dyskinesia and Type II Schizophrenia

1992 ◽  
Vol 160 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Elizabeth J. B. Davis ◽  
Milind Borde ◽  
L. N. Sharma
Keyword(s):  
Cognitive Impairment ◽  
Negative Symptoms ◽  
Chronic Schizophrenia ◽  
Thought Disorder ◽  
Control Group ◽  
Positive Symptoms ◽  
Type Ii ◽  
Formal Thought Disorder ◽  
Schizophrenic Patients ◽  
Male Patients

Cognitive impairment, negative and positive symptoms, primitive release reflexes, and age/temporal disorientation were assessed in 20 male patients meeting the DSM–III–R criteria for chronic schizophrenia and Schooler & Kane's criteria for TD. The control group comprised 20 age-matched male chronic schizophrenic patients without TD. Significant associations were found between TD, cognitive impairment, some negative symptoms, and formal thought disorder. These associations were independent of other illness and treatment variables. The severity of TD correlated significantly with that of cognitive impairment.

Theory of mind in the early course of schizophrenia: stability, symptom and neurocognitive correlates, and relationship with functioning

2015 ◽  
Vol 45 (10) ◽  
pp. 2031-2043 ◽  
Author(s):  
J. Ventura ◽  
A. Ered ◽  
D. Gretchen-Doorly ◽  
K. L. Subotnik ◽  
W. P. Horan ◽  
...  
Keyword(s):  
Theory Of Mind ◽  
Negative Symptoms ◽  
Chronic Schizophrenia ◽  
First Episode ◽  
Positive Symptoms ◽  
Healthy Controls ◽  
Role Functioning ◽  
Recent Onset ◽  
Early Course ◽  
The Relationship

BackgroundNumerous studies have reported links between theory of mind (ToM) deficits, neurocognition and negative symptoms with functional outcome in chronic schizophrenia patients. Although the ToM deficit has been observed in first-episode patients, fewer studies have addressed ToM as a possible trait marker, neurocognitive and symptom correlations longitudinally, and associations with later functioning.MethodRecent-onset schizophrenia patients (n = 77) were assessed at baseline after reaching medication stabilization, and again at 6 months (n = 48). Healthy controls (n = 21) were screened, and demographically comparable with the patients. ToM was assessed with a Social Animations Task (SAT), in which the participants’ descriptions of scenes depicting abstract visual stimuli ‘interacting’ in three conditions (ToM, goal directed and random) were rated for degree of intentionality attributed to the figures and for appropriateness. Neurocognition, symptoms and role functioning were also assessed.ResultsOn the SAT, patients had lower scores than controls for both intentionality (p < 0.01) and appropriateness (p < 0.01) during the ToM condition, at baseline and 6 months. The ToM deficit was stable and present even in remitted patients. Analyses at baseline and 6 months indicated that for patients, ToM intentionality and appropriateness were significantly correlated with neurocognition, negative symptoms and role functioning. The relationship between ToM and role functioning was mediated by negative symptoms.ConclusionsThe ToM deficit was found in recent-onset schizophrenia patients and appears to be moderately trait-like. ToM is also moderately correlated with neurocognition, negative and positive symptoms, and role functioning. ToM appears to influence negative symptoms which in turn makes an impact on role functioning.

scholarly journals Cannabis use and abuse correlates in a homogenous South African schizophrenia population

2009 ◽  
Vol 15 (1) ◽  
pp. 5 ◽  
Author(s):  
Liezl Koen ◽  
Regan Jonathan ◽  
Dana JH Niehaus
Keyword(s):  
South African ◽  
Functional Outcomes ◽  
Negative Symptoms ◽  
Age Of Onset ◽  
Cannabis Use ◽  
Positive Symptoms ◽  
International Studies ◽  
Formal Thought Disorder ◽  
Schizophrenic Patients

<p><strong>Objective.</strong> Worldwide, cannabis is the most widely used illicit substance, and it has been identified as a correlate in schizophrenia samples for poorer symptomatic and functional outcomes in many international studies. The object of this retrospective study was to identify the prevalence of cannabis use/abuse and the demographic and clinical correlates therefor in a large homogeneous South African schizophrenia population.</p><p><strong>Methods.</strong> As part of a large genetic study, 547 subjects with a diagnosis of schizophrenia were recruited. Demographic and clinical data were collected and each participant underwent a urinary drug screen. Use/abuse of cannabis was defined as using cannabis more than 21 times in a single year. Subjects with and without cannabis use/abuse were statistically compared. <strong></strong></p><p><strong>Results.</strong> Significant differences between the two groups were found in terms of gender, marital status, age of onset of schizophrenia, number of hospitalisations and relapses, alcohol abuse, smoking, the Scale for the Assessment of Positive Symptoms (SAPS) scores for hallucinations, delusions, bizarre behaviour and formal thought disorder, and the Scale for the Assessment of Negative Symptoms (SANS) score for avolition/apathy. <strong></strong></p><p><strong>Conclusion.</strong> The prevalence of cannabis use/abuse in this study was high, and our findings were comparable with those of previous international studies. Abuse/use started mainly in the teenage years, was more prevalent among males than females, and was associated with negative overall outcomes. There was also a positive correlation between cannabis and nicotine and alcohol use/abuse. Determination of cannabis abuse based solely on history was found to be reliable, and urine cannabis testing appeared to be of limited value in routine management of this group of schizophrenic patients.</p>

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