Behavior In Schizophrenic Patients Research Articles

P-1222 - Decision making in schizophrenia: a neuroeconomic trial on social cognition

Introduction We have studied the strategic behaviour of schizophrenic patients playing the Dictator Game (DG) and the Ultimatum Game (UG). The model of Homo economicus predicted by traditional economical theories describes the individual involved in economical negotiations as a selfish, rational trader, whose leading purpose is to maximize his utility function. Neuroeconomy contradicts this model supplying data that show a more emotive, irrational behaviour in normal people involved in bargaining tasks. Objective To study how people affected by schizophrenia allocate a resource when asked if sharing it or not, and how their behaviour change during a negotiation, in which strategic mentalizing can help to gain some good. Aim To demonstrate that schizophrenic patients would not show an increment in their offers as Proposers in UG compared to DG and would not refuse unfair offers as Responders. Methods 19 schizophrenic patients and 10 controls were tested with DG and UG. Participants underwent 24 trials of DG as Dictators, 24 trials of UG as Offerers and 24 trials of UG as Responders. Results In the schizophrenic group UG mean offers were not significantly higher than DG offers, while controls showed the opposite. Compared to controls, schizophrenic patients showed a higher propensity to accept unfair offers. Moreover schizophrenic patients' behaviour was not influenced by the type of player (avatar vs human being). Conclusions Our study presents data that assimilate schizophrenic subjects to homo economicus: in fact, compared to normal people, schizophrenic patients show “more rational” bargaining behaviour, due to ToM deficit.

Aggressive behaviour in schizophrenic patients after abrupt treatment discontinuation

Objective. This retrospective study examined the demographic, clinical and pharmacological factors associated with aggressive behaviour after abrupt discontinuation of medication in schizophrenic patients. Method. The study reports on a survey of 402 schizophrenic patients, who had abruptly discontinued their medication and had been involuntarily hospitalized to Psychiatric Hospital of Attika. The survey utilized the Discontinuation-Emergent Signs and Symptoms Checklist (DESS) to assess the signs and symptoms that patients exhibited (Rosenbaum et al., Biol Psychiatry 1998;44:77), as well the Aggression Scale (Delgado-Escueta et al., New England J Med 1981;305:711) to estimate the aggressive behaviour. Demographic and clinical variables as well as variables related to pharmacological treatment have been also investigated. Results. Analyses revealed that the presence of aggressive behaviour after abrupt drug discontinuation was associated positively with previous history of aggression, male gender , abrupt discontinuation of anticholinergics, delusions, nervousness or anxiety, elevated mood, irritability and negatively with negative symptoms. These predictors can correctly classify 76.3% of patients with aggressive behaviour and 64.0% of patients without aggressive behaviour. Conclusion. These findings suggest that abrupt discontinuation of medication in schizophrenic patients may lead to aggressive behaviour, being connected at least in the acute phase with particular demographic, clinical and pharmacological parameters.

U n estudio exploratorio de los procesos referenciales en pacientes esquizofrénicos crónicos

The behavior of schizophrenic patients as speakers and listeners was analised duringa communicative task, evaluating effect of modeling on these behaviors.Four female patients diagnosed as schizophrenic participated in this study. A betweensubjects design was used, in which individual training and group evaluation sessionswere altemated. Remlts point out that patients: a) did not describe differentially basedon thematic orantaned and/or contained elements related to stimuli; b) showed a high frecuencyof questioning when differential descriptions, and e) modeling had short·termeffects, without generalization to new stimuli in the same task.

P03-22 - Perturbations in p50 auditory evoked potential and hallucinatory behavior in schizophrenia

Earlier findings suggested auditory evoked potentials as diagnostic measure in schizophrenia. However, the relationship between different components of middle latency auditory evoked response (MLAER) and clinical symptoms of schizophrenia is unclear. In this study we explored the relationship between the amplitude of P50 potential and hallucinatory behavior in medicated schizophrenic patients. MLAER from thirty seven outpatient, clinically stable medicated schizophrenic patients (mean age 43.5 years, SD = 11.7), twenty six males, were measured. The evoked potentials were elicited in a paired click paradigm. The amplitude of P50, measured from pre-stimulus baseline, was studied. The bandpass filter was 1-50 Hz. Twenty seven (20 males) patients experienced hallucinatory behavior. Schizophrenic patients with hallucinatory behavior had significantly (p< 0.05) smaller P50 amplitude, elicited by both first and second clicks in the pair. No significant differences were found for P50 amplitudes, measured from preceding negative deflection. Preliminary analysis suggests that the amplitude of the P50 auditory potential, measured from the pre-stimulus baseline in a paired click paradigm is related to hallucinatory behavior in schizophrenic patients.

342 – Impact of different antipsychotic on ghrelin and food behavior in schizophrenic patients

342 – Impact of different antipsychotic on ghrelin and food behavior in schizophrenic patients

Temperament and character in violent schizophrenic patients

Preliminary evidence shows that personality traits are important in determining violent behavior in schizophrenia. As only some patients with schizophrenia show a greater risk for violence, this risk may therefore be considered as dynamic, varying as a function of the extent to which certain personality dimensions are present and the degree to which environmental events moderate or exacerbate their expression. ObjectiveTo compare temperament and character dimensions between violent and non-violent schizophrenic patients and to determine which temperament and character dimensions are predictors of violent behavior in schizophrenia. MethodWe recruited 102 schizophrenic patients without concomitant substance abuse 4 months prior to the assessment. Diagnoses were based on the SCID-I. Personality dimensions were assessed with the Temperament and Character Inventory and violent behaviors with the Overt Aggression Scale. ResultsHigher levels of the temperament dimension novelty seeking and a lower cooperativeness, as a character dimension, were risk factors for violent behavior in schizophrenic patients. DiscussionOur data indicate that schizophrenic patients will show a greater risk for violence according to certain personality configurations and the degree to which environmental events moderate or exacerbate their expression.

Mental state attribution, neurocognitive functioning, and psychopathology: What predicts poor social competence in schizophrenia best?

Background Research into mental state attribution has repeatedly shown that patients with schizophrenia are impaired in their capacity to reflect upon their own and others' beliefs, knowledge and intentions, with important confounds being executive functioning, intelligence, duration of illness, and medication. Furthermore, the extent to which impaired mental state attribution, neurocognition and psychopathology explain abnormal social behavior in schizophrenic patients has been a matter of debate. We sought to determine whether mental state attribution in schizophrenia predicts poor social competence better than “non-social” cognitive factors or psychopathology. Methods Intelligence, executive functioning, mental state attribution, psychopathology and social behavior were assessed in 38 patients diagnosed with schizophrenia according to DSM-IV criteria and compared with 29 healthy controls paralleled for age and sex. All patients received antipsychotic treatment, and all participants had no history of substance abuse or traumatic brain injury. Results In the entire schizophrenia group impaired mental state attribution alone accounted for about 50% of the variance of deviant social behavior, whereas the PANSS positive score and the duration of illness contributed an additional small amount of variance. This effect was even more pronounced in a subgroup of patients with at least normal intelligence, where neither the PANSS score nor the chronicity of the disorder remained significant predictors of poor social competence. Medication was not associated with any one of the neurocognitive measures including mental state attribution, psychopathology or social behavior. Conclusions Impaired capacity to appreciate one's own and others' mental states is the single-best predictor of poor social competence in schizophrenia, and should perhaps be included in future definitions of the “core” symptomatology of schizophrenic disorders.

Violent behavior in schizophrenic patients: relationship with clinical symptoms

AbstractConsiderable evidence suggests that violent behavior observed in schizophrenic patients is motivated by psychotic symptomatology. The understanding of violence in schizophrenic patients requires consideration of psychiatric symptomatology. Objective: This study investigated the relationship between violent behavior and psychiatric symptomatology in schizophrenic patients. Method: One hundred and thirteen patients were recruited. Thirteen patients were excluded due to concomitant substance abuse six months prior to the assessment. Diagnoses were based on the SCID‐I. Psychotic symptom severity was assessed with the PANSS. Violent behaviors were assessed with the OAS. Results: Violent behaviors were associated with more severe psychotic symptomatology including hallucinations, delusions, excitement, poor impulse control, and thinking disturbances. Conclusions: Patients with exacerbation of psychotic symptomatology have an increased risk of violent behavior. It is necessary to determine which subtypes of hallucinations and delusions are implicated in the association of schizophrenia and violent behavior. Violent behavior in schizophrenic patients is a heterogeneous phenomenon best explained in the context of specific symptoms associated with violence and course of illness. The retrospective assessment of the variables raises methodological questions concerning the reliability of measurement of the impact of psychotic symptoms on violence. Aggr. Behav. 00:1–10, 2005. © 2005 Wiley‐Liss, Inc.

Premorbid adjustment and violent behavior in schizophrenic patients

We examined the influence of premorbid adjustment on violent behavior in schizophrenic patients. There is some evidence that poor premorbid adjustment predicts violent behavior, then we decided to examine this hypothesis further. Method: We recruited 72 schizophrenic patients without concomitant substance abuse 6 months prior to the assessment. Diagnoses were based on the SCID-I. Premorbid adjustment was evaluated with the Premorbid Adjustment Scale and violent behaviors with the Overt Aggression Scale. Results: Violent schizophrenic patients showed an overall worse premorbid adjustment during childhood. In addition, the area of “peer relationships” was significantly diminished in several life period sections such as childhood, early and late adolescence in violent patients. Discussion: Our data indicate that difficulties in social relationships during early stages of life may increase the risk of future violent behavior among schizophrenic patients.

BLOOD ZINC AND COPPER CONCENTRATIONS IN CRIMINAL AND NONCRIMINAL SCHIZOPHRENIC MEN

This study investigated the effects of zinc and copper on the behavior of schizophrenic patients by comparing blood zinc and copper levels in criminal and noncriminal schizophrenic patients. Of the total 88 subjects, 44 were patients with schizophrenia and no criminal record who were being treated at the Elazig Mental Hospital and 44 were schizophrenic patients who had committed a crime and were sent to the same hospital upon a court order for monitoring, detention, and treatment. Of the subjects with criminal records, 31 (70%) had committed a violent crime and 13 (30%) had committed a nonviolent crime. The mean plasma zinc value was 68 &#45 1.55 &#119 g/dL in the criminal subjects and 81 &#45 2.73 &#119 g/dL in the noncriminal subjects ( p =.001). The mean serum copper value was 104 &#45 1.80 &#119 g/dL in criminal subjects and 93 &#45 2.92 &#119 g/dL in noncriminal subjects ( p =.02). Mean plasma zinc values were significantly lower in criminal subjects when compared to noncriminal subjects, while mean serum copper values were significantly higher in criminal subjects than noncriminal subjects.

Metabotropic glutamate subtype 5 receptors modulate locomotor activity and sensorimotor gating in rodents.

Use-dependent N-methyl-d-aspartate receptor (NMDAR) antagonists produce behaviors in human volunteers that resemble schizophrenia and exacerbate those behaviors in schizophrenic patients, suggesting that hypofunction of NMDAR-mediated neuronal circuitry may be involved in the etiology of clinical schizophrenia. Activation of the metabotropic glutamate receptor subtype 5 (mGluR5) enhances NMDAR-mediated currents in vitro. Thus, activation of mGluR5 could potentiate hypofunctional NMDARs in neuronal circuitry relevant to schizophrenia. To further elucidate the role of mGluR5, the present study examined the effects of mGluR5 antagonist administration, with and without coadministration of the use-dependent NMDAR antagonist phencyclidine (PCP), on locomotor activity and prepulse inhibition (PPI) of the acoustic startle response in rodents. We further examined PPI in mGluR5 knockout mice. Finally, we examined PPI after administration of the mGluR5 agonist 2-chloro-5-hydroxyphenylglycine (CHPG) alone and in combination with amphetamine. The data indicate that the mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine has no effect on locomotor activity or PPI by itself but does potentiate both PCP-induced locomotor activity and disruption of PPI. We further found that mGluR5 knockout mice display consistent deficits in PPI relative to their wild-type controls. Finally, the data indicate that CHPG has no effect on PPI by itself, but ameliorates amphetamine-induced disruption of PPI. Collectively, these data suggest that mGlu5 receptors play a modulatory role on rodent PPI and locomotor behaviors and are consistent with the hypothesis that mGlu5 agonist/potentiators may represent a novel approach for antipsychotic drug development.

Blood zinc and copper concentrations in criminal and noncriminal schizophrenic men.

This study investigated the effects of zinc and copper on the behavior of schizophrenic patients by comparing blood zinc and copper levels in criminal and noncriminal schizophrenic patients. Of the total 88 subjects, 44 were patients with schizophrenia and no criminal record who were being treated at the Elazig Mental Hospital and 44 were schizophrenic patients who had committed a crime and were sent to the same hospital upon a court order for monitoring, detention, and treatment. Of the subjects with criminal records, 31 (70%) had committed a violent crime and 13 (30%) had committed a nonviolent crime. The mean plasma zinc value was 68 +/- 1.55 microg/dL in the criminal subjects and 81 +/- 2.73 microg/dL in the noncriminal subjects ( p = .001). The mean serum copper value was 104 +/- 1.80 microg/dL in criminal subjects and 93 +/- 2.92 microg/dL in noncriminal subjects (p = .02). Mean plasma zinc values were significantly lower in criminal subjects when compared to noncriminal subjects, while mean serum copper values were significantly higher in criminal subjects than noncriminal subjects.

Command Hallucinations: Who Obeys and Who Resists When?

The impact of auditory command hallucinations on the behaviour of schizophrenic patients sometimes appears to be unpredictable. In order to tackle this problem, the psychopathological characteristics of command hallucinations in 31 schizophrenic patients were assessed using a 24-item questionnaire. Using binary data and relative risk analysis methods, predictors were determined for obeying or resisting command hallucinations. Characteristics of voices and the attitude toward the voices appear equally important for prediction. A set of three psychopathological characteristics comprising a voice known to the patient, emotional involvement during the hallucinations, and seeing the voice as real provides significant predictivity of behaviour following command hallucinations. These results are interesting for clinical and forensic psychiatrists.

Eye movements during the Rorschach test in schizophrenia.

In order to understand relationships between scanning behaviors, characteristics of visual stimuli and the clinical symptoms in schizophrenia, eye movements of 37 schizophrenic patients and 36 controls were recorded using an eye-mark recorder during a free-response period in a Rorschach test. Four cards (I, II, V and VIII) were used. Data were analyzed during 15 s from the presentation of each card. For all cards, the number of eye fixations and the number of eye fixation areas were fewer, and total scanning length and mean scanning length were shorter for schizophrenic patients than for controls. For card II, in the non-popular response group, eye fixation frequency upon area 5 + 6 (red) was higher for schizophrenic patients. For card VIII, in the popular response group, eye fixation frequency upon area 5 + 6 (pink) was lower for schizophrenic patients. For cards II and VIII, the number of eye fixations was inversely correlated with negative symptoms. For card II, total scanning length tended to be inversely correlated with negative symptoms, and mean eye fixation time was correlated with negative symptoms. The number of eye fixation areas was inversely correlated with positive symptoms. For card VIII, eye fixation frequency in a stimulative area tended to be correlated with positive symptoms. Scanning behaviors in schizophrenic patients are affected by characteristics of visual stimuli, and partially by clinical symptoms.

Dexamethasone suppression test and suicide attempts in schizophrenic patients

The suicide attempts were assessed in 32 schizophrenic patients on whom the dexamethasone suppression test (DST) was done twice in the course of illness: in the years 1985–91 and 1996–97. In the 1985–91 period, both baseline and post-dexamethasone cortisol levels were significantly higher in the patients with previous suicide attempts and baseline cortisol was higher in the patients who were to make a future attempt. In 1996–97, DST non-suppression was shown in more than half of the patients with a history of suicide attempt and in none of those without such history: all cortisol levels were significantly higher in the patients with a history of suicide attempt. Although the mean intensity of depression was higher in the patients with a history of suicide attempt, no association between the intensity of depression and present or previous DST non-suppression status was found. It is suggested that the hyperactivity of the hypothalamic-pituitary-adrenal axis may constitute an element of diathesis for suicidal behavior in schizophrenic patients.

Trait contributions of complex dysregulated behavioral organization in schizophrenic patients

Background: The “temporal architecture” of behavior is a construct that can be used to quantify the structure of behavioral sequences in the temporal domain—for example, by using a two-choice prediction task to investigate how past responses, stimuli, and outcomes influence the decision-making process. Using this task, previous investigations of the temporal architecture of the behavior in schizophrenic patients have identified an increased frequency of alternating highly predictable and highly unpredictable response sequences in the same test session in the same patient. Here, the hypothesis is tested that this dysregulation is stable over time and independent of psychosocial factors and symptomatic fluctuations. Methods: Ninety-one schizophrenic patients were tested on a 128 trial version of the two-choice prediction task; of those, 58 subjects completed a retest session 40 days later. Three sets of measures were obtained: simple response biases, dynamical entropy, and mutual information functions. These measures were subjected to a factor analysis, and the reliability of the resulting factors was examined. Results: First, three factors were obtained, which quantify 1) the level of dysregulation on this task; 2) the extent to which a win-stay/lose-shift strategy was used; and 3) the amount of simple response perseveration. Second, Crohnbach α for these factors was .699, .721, and .458, respectively. Third, there were no significant differences in the level of these factors within individual patients at the two time points. Fourth, neither symptom measures (Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms subscale scores) nor psychosocial or clinical variables (age, gender, illness duration, medication status) were able to predict the level of these factors at test or at retest. Conclusions: These results support the hypothesis that the fundamental dysregulation of the temporal architecture of behavior in schizophrenic patients is stable across time and independent of symptomatic status. Future studies will examine the heritability of this dysfunction.

Studying planning in graphic production: Evidence for more stereotyped behaviour in schizophrenic patients compared to depressed patients and controls

Studying planning in graphic production: Evidence for more stereotyped behaviour in schizophrenic patients compared to depressed patients and controls

Homicidal behavior in schizophrenia associated with a genetic polymorphism determining low catechol O-methyltransferase (COMT) activity

Although aggressive, violent, and dangerous behavior in man has multifactorial causes, genetic factors are estimated by twin and adoption studies to substantially contribute to the development of such conduct. Recently, homozygosity of a low enzyme activity variant of the catechol O-methyltransferase (COMT) gene was reported to be associated with aggressive behavior in a group of schizophrenic patients. We observe a similar tendency in a group of 30 schizophrenic patients who were confined to a maximum-security psychiatric facility for homicide. Significant excess (46.7% versus 21.0%) homozygosity of the low activity COMTmet/met genotype was observed in 30 mostly male (28 of 30) homicidal schizophrenic patients compared with 415 control subjects (Pearson chi(2) = 10.53, P = 0.005, df = 2). No difference in COMT genotype was found between 62 nonviolent schizophrenic patients and the 415 control subjects (chi(2) = 0.963, P > 0.1, df = 2). A trend for excess (46.7% versus 25.8%) homozygosity of the low activity COMTmet/met genotype was also observed when the homicidal schizophrenic subjects were compared directly with the nonviolent schizophrenic patients (chi(2) = 4.03, P = 0.1, df = 2). Similarly, an excess of the low activity COMTmet allele was observed in homicidal versus nonviolent schizophrenic patients (chi(2) = 2.92, P = 0.087, df = 2). Similar results were obtained if only male subjects were examined. No significant difference was found between control (257 Ashkenazi and 152 non-Ashkenazi Jews) COMT genotypes in the two principal ethnic groups examined (chi(2) = 3.79, P > 0.1, df = 2). Finally, no association was observed between homicidal behavior in schizophrenic patients and the dopamine D4 exon III repeat length polymorphism (D4DR) and the serotonin transporter promoter-region polymorphism (5-HTTLPR). Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:628-633, 1999.

The nonlinear, complex sequential organization of behavior in schizophrenic patients: neurocognitive strategies and clinical correlations

Background: Thought disorder is a hallmark of schizophrenia and can be inferred from disorganized behavior. Measures of the sequential organization of behavior are important because they reflect the cognitive processes of the selection and sequencing of behavioral elements, which generate observable and analyzable behavioral patterns. In this context, sequences of choices generated by schizophrenic patients in a two-choice guessing task fluctuate significantly, which reflects an “oscillating dysregulation” between highly predictable and highly unpredictable subsequences within a single test session. In this study, we aimed to clarify the significance of dysregulation by seeing whether demographic, clinical, neuropsychological, and psychological measures predict the degree of dysregulation observed on this two-choice task. Methods: Thirty schizophrenic patients repeatedly performed a LEFT or RIGHT key press that was followed by a stimulus, which occurred randomly on the left or right side of the computer screen. Thus, the stimulus location had nothing to do with the key press behavior. The range of key press sequence predictabilities as measured by the dynamical entropy was used to quantify the dysregulation of response sequences and reflects the range of fixity and randomness of the responses. A factor analysis was performed and step-wise multiple regression analyses were used to relate the factor scores to demographic, clinical, symptomatic, Wisconsin Card Sorting Test (WCST), and Rorschach variables. Results: The LEFT/RIGHT key press sequences were determined by three factors: 1) the degree of win-stay/lose-shift strategy; 2) the degree of contextual influence on the current choice; and 3) the degree of dysregulation on the choice task. Demographic and clinical variables did not predict any of the three response patterns on the choice task. In contrast, the WCST and Rorschach test predicted performance on various factors of choice task response patterns. Conclusions: Schizophrenic patients employ several rules, i.e., “win-stay/lose-shift” and “decide according to the previous choice,” that fluctuate significantly when generating sequences on this task, confirming that a basic behavioral dysregulation occurs in a single schizophrenic subject across a single test session. The organization or the “temporal architecture” of the behavioral sequences is not related to symptoms per se, but is related to deficits in executive functioning, problem solving, and perceptual organizational abilities.

Criminal and violent behavior in schizophrenic patients: an overview.

An overview of the most important older and newer results regarding the relationship between violent and criminal behavior on the one hand and schizophrenic illness on the other hand is presented. Four different methods are available to study this relationship: (i) study of the prevalence of mental illness in criminal/violent populations; (ii) study of criminality/violence rate in samples of psychiatric patients; (iii) study of criminality/violence in community samples comparing mental patients with non-patient community residents; and (iv) study of criminality/violence in birth cohorts prospectively. All these methods have been used; but samples composed of schizophrenic patients exclusively were only exceptionally studied. The results indicate that there is a modest but significant relationship between schizophrenia and violence and crime which persists even after controlling for demographic and socio-economic variables. The probability of schizophrenic patients to be criminal or violent depends on the acuity of their illness and is increased by their use of psychoactive substances. Generally, however, violent and criminal acts directly attributable to mental illness account only for a very small proportion of such acts in the society.