HLA-B27 as a possible genetic marker of psychoticism

In an earlier study HLA-B27 was found to correlate with some subgroups of schizophrenia, having an increased incidence specially in the subgroup of patients with poor prognostic features.In order to study a possible association between the P-score from the Eysenck Personality Questionnaire and HLA-B27, two subgroups of chronic paranoid schizophrenic patients selected according to the same diagnostic criteria were compared. P-scores were significantly higher in the subgroup of patients showing HLA-B27, when compared with patients without HLA-B27 (p < 0.02).This finding gives support to the hypothesis of a genetic factor underlying P, and indicates the possibility of using P-scores in the selection of more homogeneous patients groups for other researches, as well as a factor in prognostic prediction.     

Autobiographical Memory and Suicide Attempts in Schizophrenia

According to the cry of pain model of suicidal behavior, an over‐general autobiographical memory function is often found in suicide attempters. The model has received empirical support in several studies, mainly of depressed patients. The present study investigated whether deficits in autobiographical memory may be associated with an increased frequency of suicide attempts in patients with schizophrenia. We found support for our hypothesis that patients with schizophrenia and previous suicide attempts have an over‐generalized autobiographical memory compared to patients with schizophrenia without previous suicide attempts. Adjustment for sociodemographic and clinical variables did not change the results.     

On "risk" and reward: investigating state anhedonia in psychometrically defined schizotypy and schizophrenia

Anhedonia, defined as dysfunction in the experience of pleasant emotions, is a hallmark symptom of the schizophrenia spectrum. Of interest, it is well documented that patients with schizophrenia, at least as a group, do not show reductions in their state experience of pleasant stimuli. However, there is emerging evidence to suggest that individuals with schizotypy--defined as the personality organization reflecting the latent vulnerability for schizophrenia--do show these state deficits. This is paradoxical in that schizophrenia reflects a more pathological state in virtually every conceivable domain as compared with schizotypy. The present study examined self-reported affective reactions to neutral-, bad-, and good-valenced stimuli in individuals with psychometrically defined schizotypy and schizophrenia. Two separate control groups were also included, comprising psychometrically defined controls and stable outpatients with affective disorders. With no exceptions, the schizotypy group reported significantly less pleasant affect for each of the three conditions than each of the other groups. Conversely, the schizophrenia group did not statistically differ from the control groups for any of the conditions. Within both the schizotypy and schizophrenia groups, severity of negative symptoms/traits was associated with less pleasant report. We found that individuals with prominent negative symptoms and traits from the schizophrenia and schizotypy groups resembled each other in terms of state anhedonia. The present findings did not appear to reflect comorbid depression or anxiety. Our discussion centers on this apparent paradox in the schizophrenia spectrum--that individuals with schizotypy exhibit state anhedonia, whereas patients with schizophrenia do not.     

Event-related FMRI study of context processing in dorsolateral prefrontal cortex of patients with schizophrenia

Context processing is conceptualized as an executive function involved in voluntary, complex actions such as overcoming automatic responses. The present study tested the hypothesis that context-processing deficits in patients with schizophrenia are associated with a dysfunction of left dorsolateral prefrontal cortex (DLPFC). Using event-related functional magnetic resonance imaging (fMRI), 17 controls and 17 medicated patients performed a version of the AX task in which a learned, automatic response had to be inhibited. In controls, left DLPFC activity increased when preparing to overcome an automatic response, whereas patients with schizophrenia showed no differential activation. In controls, context processing appeared to be associated with the differential representation of cues associated with the need to provide top-down support for overcoming automatic responses. This mechanism appeared to be impaired in patients with schizophrenia.     

The temporal organization of functional brain connectivity is abnormal in schizophrenia but does not correlate with symptomatology

Previous work employing graph theory and nonlinear analysis has found increased spatial and temporal disorder, respectively, of functional brain connectivity in schizophrenia. We present a new method combining graph theory and nonlinear techniques that measures the temporal disorder of functional brain connections. Multichannel electroencephalographic data were windowed and functional networks were reconstructed using the minimum spanning trees of correlation matrices. Using a method based on Shannon entropy, we found elevated connection entropy in gamma activity of patients with schizophrenia; however, gamma connection entropy remained elevated in patients with schizophrenia even after a reduction in symptoms due to treatment with antipsychotics. Our results are consistent with several possibilities: (1) aberrant functional connectivity is epiphenomenal to schizophrenia, (2) aberrant functional connectivity is a central feature but antipsychotics reduce symptoms by an independent mechanism, or (3) connection entropy is not an appropriately sensitive measure of brain abnormalities in schizophrenia.     

Schizophrenia outpatients' perceptions of their parents: is expressed emotion a factor?

The factors that mediate the association between expressed emotion (EE) and relapse in schizophrenia patients are still unknown. Many researchers hypothesize that interactions with high-EE individuals are stressful for patients, leaving them vulnerable to relapse. It would be useful to investigate whether patients perceive interactions with high-EE parents as stressful. In this study, associations were examined between levels of EE in parents and the types of personal memories patients had about these parents. EE ratings were obtained for both parents of 27 schizophrenia outpatients, and patients were asked to describe "happy, nonstressful" memories and "unhappy, stressful" memories during 2 interviews. Patients recounted fewer nonstressful memories and more stressful memories about high-versus low-EE parents. Implications of these results are discussed.     

Understanding the executive functioning heterogeneity in schizophrenia

Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia patients. Furthermore, it is still unknown if the executive impairments observed in schizophrenia are better characterized as specific or as reflecting generalized cognitive factors. The four executive processes (i.e. updating, inhibition, shifting and divided attention) described in Miyake et al.'s (2000) theoretical model were examined in 62 individuals with schizophrenia and 49 healthy controls. At group level, impairments in all four executive processes confirmed the marked impairment in executive functioning in patients with schizophrenia. Statistical analysis indicated that executive performances in schizophrenia patients were more heterogeneous than in healthy controls. Compared with standardized norms, 94% of patients exhibited impairment in at least one of the executive tasks. Twenty-one percent of patients exhibited impairment in one executive task, 27% in two tasks, 23% in three executive tasks and 23% exhibited impairments in the four executive tasks. Six percent of patients had normal executive profile. Regression analysis indicated that only premorbid intellectual quotient and a general slowing in processing speed predicted the executive dysfunction severity. Executive functioning was not affected by age, duration of illness, psychotic status, or by antipsychotic dosage. Our results emphasize the heterogeneity of the dysexecutive syndrome in schizophrenia when individual profile analysis is considered, and extend the view that individual cognitive differences in schizophrenia are largely underlined by general cognitive factors such as intellectual level and general processing speed.     

Drug treatment refusal,diagnosis, and length of hospitalization in involuntary psychiatric patients

A retrospective study of 664 involuntary psychotic inpatients who were discharged in a 27-month period indicated that 18% refused antipsychotic drug treatment. Statistical differences between refusers and consenters were found in diagnosis, length of hospitalization, and dosage of antipsychotic medications prescribed at the time of discharge. Compared with consenters, refusers were more often diagnosed as having bipolar or schizoaffective disorder while a majority of consenting patients were diagnosed as having schizophrenia. The variance in length of stay was explained by diagnosis alone. Refusers were receiving antipsychotic medication at discharge of one-half the average daily dosage of consenters. Both refusal status and diagnosis were found to contribute statistically to the variance in antipsychotic drug dosage.     

Projecting the self into the future in individuals with schizophrenia: a preliminary cross-sectional study

The ability to project oneself into the future contributes to development and maintenance of a coherent sense of identity. If recent research has revealed that schizophrenia is associated with difficulties envisioning the future, little is known about patients’ future self-representations. In this study, 27 participants with schizophrenia and 26 healthy controls were asked to simulate mental representations of plausible and highly significant future events (self-defining future projections, SDFPs) that they anticipate to happen in their personal future. Main results showed that schizophrenia patients had difficulties in reflecting on the broader meaning and implications of imagined future events. In addition, and contrary to our hypothesis, a large majority of SDFPs in schizophrenia patients were positive events, including achievements, relationship, and leisure contents. Interestingly, patients and controls did not differ on the perceived probability that these events will occur in the future. Our results suggest that schizophrenia patients have an exaggerated positive perception of their future selves. Together, these findings lend support to the idea that past and future self-defining representations have both similar and distinct characteristics in schizophrenia.     

寻找镜中的自我：精神分裂症患者的视觉观点采择

精神分裂症患者的视觉观点采择影响其必要的社交活动和生活质量。本文通过对精神分裂症患者视觉观点采择的研究进行梳理,总结出相关的心理特点：精神分裂症患者的视觉观点采择过程受损,表现出自我中心性和他人中心性。在神经生理上表现出与视觉观点采择相关的脑区激活减弱。可能的原因是患者认知功能中反应抑制能力和心理旋转能力的受损所致,建议采用认知干预疗法可能会改善患者的视觉观点采择能力。目前的研究论证了精神分裂症患者视觉观点采择过程的损伤,对于不同水平的视觉观点采择下精神分裂症患者的认知模式还未有明确的定论,未来的研究可以从该角度入手,更加明确精神分裂症患者不同水平视觉观点采择的特点和神经生理活动。     

The relationship between cognitive inhibition and psychotic symptoms

Cognitive models of schizophrenia have highlighted deficits of inhibitory attentional processes as central to the disorder. This has been investigated using "negative priming" (S. P. Tipper, 1985), with schizophrenia patients showing a reduction of negative priming in a number of studies. This study attempted to replicate these findings, but studied psychotic symptoms rather than the broad diagnostic category of schizophrenia. Psychotic individuals exhibiting positive symptoms were compared with asymptomatic psychiatric patients and with a normal control group. As predicted, the symptomatic group failed to show the usual negative priming effect, which was present in the asymptomatic and normal groups. A modest but significant correlation was found between negative priming and delusions. Neither diagnosis, nor affective or negative symptoms, nor chronicity, nor medication, was related to negative priming. These data replicate previous findings that positive symptoms are related to a reduction in cognitive inhibition, although considerable variability was observed among the psychotic patients.     

Memory deficits in young schizophrenics with normal general intellectual function

The aim of the present study was to examine different dimensions of memory functioning in young schizophrenics with normal general intellectual abilities. Thirty-three patients with schizophrenia and 33 healthy controls were included in the study. The results suggest that immediate short-term memory is intact, though there emerged a working memory deficit in the schizophrenia group. Deficient encoding of verbal material was observed in some, but not in other, testing conditions. There also seemed to be a retrieval deficit for verbal material in schizophrenia, though no storage deficit was indicated. Impaired memory for non-verbal material was also revealed. These results occurred in a context of intact executive functioning as measured by the Wisconsin Card Sorting Test. The results indicate that temporal and frontal structures, as well as their interconnections, may be compromised in schizophrenia.     

Theory of Mind in schizophrenia: first person vs third person perspective

Patients suffering from schizophrenia have an impaired meta-representation also known as Theory of Mind (ToM). Moreover, the presence of delusions or other positive symptoms of schizophrenia has been correlated to poor ToM performances. Lack of insight is a common symptom of schizophrenia and can be considered a critical manifestation of impaired ToM abilities. In particular, the present study addresses the role of perspective ToM ability in schizophrenic patients. Thirty severely delusional schizophrenic patients completely lack insight when interviewed about their delusions. Seven subsequently gain insight about their mental state when perspective is shifted from the first person to third person. These data suggest that in some delusional schizophrenic patients, it may be possible to gain access to and modify their mental states.     

Schizotypy in relatives of patients with schizophrenia

Previous studies indicate that relatives of patients with schizophrenia are more likely to present characteristics of schizotypal personality than the general population. Few transcultural studies of schizotypy have been carried out. Most instruments constructed to measure schizotypy have been applied in specific cultures; conceivably, in other populations its components may be distributed in different ways. These cultural differences may affect the relations between schizotypy and schizophrenia. The objective of this study is to obtain data on schizotypy in relatives of patients with schizophrenia and relatives of patients with other disorders in a Latin American rural population. The results suggest that cultural factors must be taken into account in order to establish the relationship between schizotypy and schizophrenia.     

Consciousness in Schizophrenia: A Metacognitive Approach to Semantic Memory

Recent studies have shown that schizophrenia may be a disease affecting the states of consciousness. The present study is aimed at investigating metamemory, i.e., the knowledge about one's own memory capabilities, in patients with schizophrenia. The accuracy of the Confidence level (CL) in the correctness of the answers provided during a recall phase, and the predictability of the Feeling of Knowing (FOK) when recall fails were measured using a task consisting of general information questions and assessing semantic memory. Nineteen outpatients were paired with 19 control subjects with respect to age, sex, and education. Results showed that patients with schizophrenia exhibited an impaired semantic memory. CL ratings as well as CL and FOK accuracy were not significantly different in the schizophrenic and the control groups. However, FOK ratings were significantly reduced for the patient group, and discordant FOK judgments were also observed more frequently. Such results suggest that FOK judgments are impaired in patients with schizophrenia, which confirms that schizophrenia is an illness characterized by an impaired conscious awareness of one's own knowledge.     

The use of the Ego Impairment Index across the schizophrenia spectrum

The goal of this study was to assess perceptual and thought disturbance, as indexed by the Ego Impairment Index (EII; Perry & Viglione, 1991), a Rorschach-derived measure, across the schizophrenia spectrum. We hypothesized that there would be an increase in EII scores (indicating increased disturbance) across the spectrum from nonpatients to severely disturbed, hospitalized schizophrenia patients. Normal comparison participants (n = 66), students with elevated scores on either the Perceptual Aberration/Magical Ideation or the Physical Anhedonia Scales (n = 24), first-degree relatives of schizophrenia patients (n = 36), participants diagnosed with Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) schizotypal personality disorder (n = 36), outpatient schizophrenia participants (n = 33), and hospitalized schizophrenia patients (n = 56) were studied. As hypothesized, we found increased EII scores in all of the schizophrenia spectrum groups when compared against normal comparison participants. Furthermore, the EII was significantly different between the schizophrenia patients and the other schizophrenia spectrum groups. These findings support the use of the EII as a sensitive measure of perceptual and thought disturbance across the schizophrenia spectrum that yields specific information regarding the type of thinking problems that occur within schizophrenia spectrum subgroups.     

Recognition of posed and genuine facial expressions of emotion in paranoid and nonparanoid schizophrenia

Most previous research reporting emotion-recognition deficits in schizophrenia has used posed facial expressions of emotion and chronic-schizophrenia patients. In contrast, the present research examined the ability of patients with acute paranoid and nonparanoid (disorganized) schizophrenia to recognize genuine as well as posed facial expressions of emotion. Evidence of an emotion-recognition deficit in schizophrenia was replicated, but only when posed facial expressions were used. For genuine expressions of emotion, the paranoid-schizophrenia group was more accurate than controls, nonparanoid-schizophrenia patients, and depressed patients. Future research clearly needs to consider the posed versus genuine nature of the emotional stimuli used and the type of schizophrenia patients examined.     

Behavioral disorganization in schizophrenia during a daily activity: the kitchen behavioral scoring scale

Executive dysfunction has been extensively described in schizophrenia and has been found to correlate with the negative symptoms of the disease. However, executive dysfunction is usually assessed by cognitive tests, and these are not necessarily good predictors of an individual's daily functioning. This study aimed to discover whether executive dysfunction in schizophrenia can be measured by analyzing a daily routine such as cooking a meal. Behavior was scored on the basis of the optimal sequence of macrostructures (order of dishes) and microsteps (order of actions) that must be performed to prepare the meal in a minimum of time and with the smallest delay between the completion of the first and last dishes. The results showed that patients with schizophrenia make macrostructure but not micro-step sequencing errors. The number of repetitions and omissions and the delay between the completion of the first and last dish were all greater in patients than in control subjects. In patients with schizophrenia, but not in normal controls, these behavioral malfunctions were significantly correlated with both negative symptoms and performance on the executive tasks. Poor performance on the memory tests was not correlated with the behavioral malfunction. Therefore, daily functioning in schizophrenia may be specifically influenced by executive dysfunction in schizophrenia, and this can be quantitatively assessed with a behavioral scale of action sequences.     

Learning and forgetting in schizophrenia

Recent studies of patients with schizophrenia have consistently demonstrated marked deficits on measures of initial learning. However, contradictory results have been reported concerning retention and forgetting. The present study examined the level of initial and delayed recall of stories and visual figures in a group of 76 patients with schizophrenia and 51 normal controls. Schizophrenia patients demonstrated marked impairments in initial and delayed recall as well as significantly worse percentage retention scores. However, schizophrenia patients and healthy controls individually matched on level of initial recall had nearly identical delayed recall performance. The results suggest a primary deficit in the initial acquisition of information rather than an accelerated rate of forgetting in schizophrenia.     

Context-processing deficits in schizophrenia: diagnostic specificity, 4-week course,and relationships to clinical symptoms

Previous research on schizophrenia suggests that context-processing disturbances are one of the core cognitive deficits present in schizophia. However, it is not clear whether such deficits are specific to schizophrenia as compared with other psychotic disorders. To address this question, the authors administered a version of the AX Continuous Performance Test designed to assess context processing in a sample of healthy controls, patients with schizophrenia, and patients with other psychotic disorders. Participants were tested at index (when medication naive and experiencing their first contact with psychiatric services) and 4 weeks later, following medication treatment. At index, patients with schizophrenia and the psychotic comparison group demonstrated similar impairments in context processing. However, context-processing deficits improved in the psychotic comparison group at 4 weeks but did not improve in patients with schizophrenia.