People With Schizophrenia Research Articles

Differing Pattern of Mismatch Negativity Responses in Clinical and Nonclinical Voice Hearers Challenge Predictive Coding Accounts of Psychosis

BackgroundAmong people with schizophrenia (PSZ), reduced mismatch negativity (MMN) is conceptualized as evidence of disrupted prediction error signaling that underlies positive symptoms. However, this conceptualization has been challenged by observations that MMN and positive symptoms are often uncorrelated. In the current study, we tested the hypothesis that reduced MMN is associated with the presence of hallucinations and delusions specifically rather than the presence of a psychiatric illness. A second aim was to determine whether the strength of the association with positive symptoms increases for indices that reflect predictions at higher levels of abstraction. MethodsFifty-six PSZ, 34 nonclinical voice hearers, and 48 healthy comparison subjects (HCs) completed 2 MMN paradigms: one with a simple duration deviant type, and one with a higher-level, pattern-violation deviant type. We also measured the repetition positivity, which reflects the formation of auditory memory traces. ResultsWe observed that although PSZ exhibited the expected pattern of significantly reduced simple duration deviant type and reduced pattern-violation deviant type at the trend level compared with HCs, nonclinical voice hearers exhibited a pattern of simple duration deviant type and pattern-violation deviant type amplitude that was statistically similar to that of HCs (ps > .64). Similarly, PSZ exhibited a significantly reduced repetition positivity slope compared with HCs in the duration condition and a trend-level reduction compared with HCs in the pattern-violation condition. Nonclinical voice hearers did not differ from either group in repetition positivity slope in either condition. ConclusionsThese results indicate that the MMN as a prediction error signal does not reflect processes relevant for the manifestation of hallucinations and delusions.

The Effect of Cognitive Behavioral Intervention Based on Self-Management on the Ability to Control Hallucinations in People with Schizophrenia

Hallucinations are a common symptoms found in individuals with schizophrenia. These hallucination cause people with schizophrenia (PWS) to experience difficulty in controlling themselves. This has an impact on suicidal behavior, harming other people, and destroying the surrounding environment. Therefore, a cognitive behavioral intervention based on self-management is needed as a non-pharmacological therapy to help PWS control hallucinations. This study aims to identify the effect of cognitive behavioral interventions based on self-management in people with schizophrenia. This study uses a quasy-experimental two groups pretest-posttest design. The sample consists 78 inpatient respondents with schizophrenia, divided into two groups, 39 in the intervention group and 39 in control group. Technique sample in this study using purposive sampling. Research data collection uses a questionnaire instrument for the ability to control hallucinations. The data explained used statistics, such as descriptive, dependent, and independent t-tests. The research results show that there are changes in the ability to control hallucinations in the intervention group and control group before and after self-management-based cognitive behavioral intervention (p-value=0.001). There was a difference in the ability to control hallucinations between the intervention group with the control group after cognitive behavioral intervention based on self-management (p-value= 0.013). The cognitive behavioral intervention based on self-management can be used as an effective cessation intervention to improve the ability of PWS to control hallucinations so that they can optimize their function in carrying out daily activities.

Longitudinal relationships between BMI and hs-CRP among people with schizophrenia

In people with schizophrenia (PwS), inflammation and metabolic issues significantly increase morbidity and mortality. However, our ability to understand inflammatory-metabolic mechanisms in this population has been limited to cross-sectional studies. This study involved 169 PwS and 156 non-psychiatric comparisons (NCs), aged 25–65, observed between 2012 and 2022 with 0 to 5 follow-ups post-baseline. High-sensitivity C-reactive protein (hs-CRP), a marker of inflammation, was measured via a particle-enhanced immuno-turbidimetric assay. Body mass index (BMI) was used as a proxy for metabolic function. The measurement intervals for hs-CRP and BMI ranged between 6 and 48 months. Linear mixed models (LMM) results revealed that at all time points, PwS has a higher hs-CRP (t (316) = 4.73, p < .001) and BMI (t (315) = 4.13, p < .001) than NCs; however, for BMI, this difference decreased over time (t (524) = −5.15, p < .001). To study interrelationships between hs-CRP and BMI, continuous time structural equational modeling (CTSEM) was used, accounting for uneven measurement intervals. CTSEM results showed that both hs-CRP predicted future BMI (Est. = 12.91, 95 % CI [7.70; 17.88]) and BMI predicted future hs-CRP (Est. = 1.54, 95 % CI [1.00; 2.04]), indicating a bidirectional relationship between inflammation and metabolic function. Notably, the influence of hs-CRP on future BMI was more robust than the other lagged relationship (p = .015), especially in PwS (Est. = 2.43, 95 % CI [0.39; 0.97]). Our study highlights the important role of inflammation in metabolic function and offers insights into potential interventions targeting inflammation in PwS.

Clinical decision-making before discharge in hospitalized persons with schizophrenia: a Spanish Delphi expert consensus.

The care of people with schizophrenia (PWS) is usually provided in an outpatient setting by community mental health teams. However, PWS frequently require inpatient treatment because of a wide array of clinical, personal and/or social situations. Unfortunately, to our knowledge, there are no guidelines available to help psychiatrists in the decision-making process on hospital discharge for PWS. The aim of this project was to develop an expert consensus on discharge criteria for PWS after their stay in an acute inpatient psychiatric unit. Using a modified Delphi method a group of 42 psychiatrists throughout Spain evaluated four areas of interest regarding this issue: clinical symptomatology, treatment-related factors, follow-up health care units after discharge, and physical health and monitoring. After two rounds, among the 64 statements, a consensus was reached for 59 (92.2%) statements. In three (17.7%) of the 17 statements on 'clinical symptomatology' and 2 (13.3%) of the 15 statements on 'follow-up health care units after discharge', a consensus was not reached; in contrast, a consensus was reached for all statements concerning 'treatment-related factors' and those concerning 'physical health and monitoring'. The consensus results highlight the importance for discharge of the control of symptoms rather than their suppression during admission and of tolerability in the selection of anantipsychotic. Although there is a lack of relevant data for guiding the discharge of PWS after hospitalization in an acute inpatient psychiatric unit, we expect that this consensus based on expert opinion may help clinicians to take appropriate decisions.

Reduce stigma for improving the treatment adherence of people with schizophrenia (PWS)

Reduce stigma for improving the treatment adherence of people with schizophrenia (PWS)

The Ethiopian Cognitive Assessment battery in Schizophrenia (ECAS): a validation study

Cognitive impairment is common in people with schizophrenia (PWS). To detect the presence and its consequences, cognitive measures with sound psychometric properties are needed. However, these are lacking especially in low-income countries. Hence, we developed the Ethiopian Cognitive Assessment battery in Schizophrenia (ECAS). In this study, we evaluated the psychometric properties of the ECAS in a cross-sectional study involving 350 PWS. Confirmatory factor analysis demonstrated a one-factor solution. ECAS score correlated significantly but weakly with a disability measure (r = −0.13, p = 0.02) and symptom dimensions of PANSS (r between −0.12 and −0.29, p < 0.05), except for positive symptoms (r = −0.10, p > 0.05). Years of education (β = 0.12, 95% CI (0.09, 0.14), p < 0.001), male sex (β = 0.22, 95% CI (0.05, 0.39)), age β = −0.02, 95% CI (−0.03, −0.01), and medication side effects (β = −0.03, 95% CI (−0.06, −0.01), p = 0.021) were significantly associated with the composite score of ECAS. The Item Response Theory analysis showed that the tool best functions among participants with moderate cognitive impairment (difficulty coefficient between −1.12 and 0.27). The Differential Item Functioning analyses showed that education had a positive contribution on Digit Symbol Substitution Test (MH OR = 2.64, 95% CI (1.34, 5.20)). The results showed that ECAS is valid in assessing cognition in PWS in low-resource settings.

External cues improve visual working memory encoding in the presence of salient distractors in schizophrenia.

People with schizophrenia (PSZ) are impaired in attentional prioritization of non-salient but relevant stimuli over salient distractors during visual working memory (VWM) encoding. Conversely, guidance of top-down attention by external predictive cues is intact. Yet, it is unknown whether this preserved ability can help PSZ encode more information in the presence of salient distractors. We employed a visuospatial change-detection task using four Gabor patches with differing orientations in 66 PSZ and 74 healthy controls (HCS). Two Gabor patches flickered which were designated either as targets or distractors and either a predictive or a non-predictive cue was displayed to manipulate top-down attention, resulting in four conditions. We observed significant effects of group, salience and cue as well as significant interactions of salience by cue, group by salience and group by cue. Across all conditions, PSZ stored significantly less information in VWM than HCS. PSZ stored significantly less non-flickering than flickering information with a non-predictive cue. However, PSZ stored significantly more flickering and non-flickering information with a predictive cue. Our findings indicate that control of attentional selection is impaired in schizophrenia. We demonstrate that additional top-down information significantly improves performance in PSZ. The observed deficit in attentional control suggests a disturbance of GABAergic inhibition in early visual areas. Moreover, our findings are indicative of a mechanism for enhancing attentional control in PSZ, which could be utilized by pro-cognitive interventions. Thus, the current paradigm is suitable to reveal both preserved and compromised cognitive component processes in schizophrenia.

Functional recovery in older adults with schizophrenia: A national interRAI study.

The concept of recovery for people with schizophrenia (PwS) is still a matter of debate. Growing numbers of PwS living to older age calls for examination of their disease trajectories with a focus on recovery. To compare two groups of PwS (good wellbeing; poor wellbeing) on several psychosocial variables associated with social wellbeing to identify interventions that support functional recovery. Data was drawn from participants from across New Zealand (NZ), who had received a formal diagnosis of Schizophrenia; were living independently in the community, and who had undergone their first International Resident Assessment Instrument (interRAI) assessment from 2012 to 2022. We compared two groups of PwS (good social wellbeing; poor social wellbeing) examining associations with demographic and psychosocial variables. We compared interRAI assessments for: 'poor psychosocial wellbeing' (n = 1,378; 67%; 56% female; 70.5% 65 years and over; 36.1% never married); and 'good psychosocial wellbeing' (n = 693; 33%; 61.1% female; 78.1% 65 years and over; 29.8% never married; n = 549 did not have sufficient social wellbeing data to be included). We found significant associations between social wellbeing and depression, disruptive behaviour, decision making, self-expression, understanding verbal information, activity level, self-reported health and medication adherence. Logistical regression showed depression (β = .84, p < .001, Wald = 51.01, Exp(B) = 2.31) and mild disruptive behaviour (β = .63, p = .002, Wald = 9.26, Exp(B) = 0.53) were the only predictors of poor social wellbeing. Those who reported some degree of depressive symptoms were 2.31 (CI [1.84, 2.91]) more likely to be in the poor social wellbeing group. A significant minority (33.5%) of older PwS enjoy positive social wellbeing. Several psychosocial variables are associated with wellbeing. By addressing the comorbidity of depressive symptoms, we may be able to improve wellbeing for older PwS.

Differences in metabolic biomarkers in people with schizophrenia who are of Mexican descent compared to non-Hispanic whites

Metabolic dysfunction is highly prevalent and contributes to premature mortality among people with schizophrenia (PwS), especially in Hispanic/Latino/a/x/e PwS, compared to non-Hispanic White (NHW) PwS. This study evaluated the relative contributions of Mexican descent and schizophrenia diagnosis to metabolic biomarker levels. This cross-sectional study included 115 PwS and 102 non-psychiatric comparison (NC) participants – English-speakers aged 26–66 years, 27% Mexican descent, and 52% women across both groups. Assessments included evaluations of BMI, psychopathology, and fasting metabolic biomarkers. We used ANOVA analyses to compare metabolic outcomes between diagnostic and ethnic subgroups, linear regression models to examine associations between Mexican descent and metabolic outcomes, and Spearman's correlations to examine relationships between metabolic outcomes and illness-related variables in PwS. Mexican PwS had higher hemoglobin A1c levels, insulin resistance, and body mass index than NHW PwS. Mexican descent was associated with higher hemoglobin A1c levels, insulin resistance, body mass index, and leptin levels, controlling for age, sex, depression, education, and smoking. Among Mexican PwS, worse negative symptoms were associated with greater insulin resistance. These findings support the possibility of ethnicity-based differences in metabolic dysregulation, though further investigation is warranted to create targeted health interventions for Hispanic PwS.

Flexibility Retained: Unimpaired Updating of Expectations in Schizophrenia.

Flexibly and actively updating expectations based on feedback is crucial for navigating daily life. Previous research has shown that people with schizophrenia (PSZ) have difficulty adjusting their expectations. However, there are studies suggesting otherwise. To explore this further, we used a novel trial-based expectation updating paradigm called attribute amnesia. In the task, the participants needed to report the location of a target stimulus among distractors in pre-surprise trials. In the surprise trial, they were unexpectedly asked to report the identity of the target before reporting its location. Afterward, control trials were conducted whereby the participants were asked the same questions as in the surprise trial. Notably, the surprise trial and control trials were nearly identical, except that the participants expected to be asked about identity information in the control trials but not in the surprise trial. Thus, an improvement in identity reporting accuracy in the control trials in comparison with the surprise trial indicated active updating of expectations. In the current study, a total of 63 PSZ and 60 healthy control subjects (HCS) were enrolled. We found that both the PSZ and the HCS were unable to report information that they had fully attended to (i.e., identity) in the surprise trial. However, both groups showed a significant improvement in reporting identity information even in the first control trial. Critically, there was no significant difference in the magnitude of improvement between the two groups. The current findings indicate that PSZ have the ability to update their expectations as quickly and flexibly as HCS, at least in the context of the current task. The possible factors that might contribute to the discrepancy regarding expectation updating are discussed.

Development and Evaluation of a Cognitive Battery for People With Schizophrenia in Ethiopia.

Cognitive difficulties significantly burdened people with schizophrenia (PWS). However, cognitive assessment is often unavailable in low- and middle-income counties (LMICs) due to a lack of validated and culturally adapted cognitive assessment tools. In this study, we developed and evaluated a culturally sensitive cognitive battery for PWS in Ethiopia. This study was conducted in three phases. First, we selected appropriate tests through an instrument selection procedure and created a new battery. Then, we rigorously adapted the tests using culturally competent procedures, including cognitive interviewing and expert meetings. Finally, we tested the new battery in 208 PWS and 208 controls. We evaluated its psychometric properties using advanced statistical techniques, including Item Response Theory (IRT). The Ethiopian Cognitive Assessment battery for Schizophrenia (ECAS) was developed from three different batteries. Participants reported tests were easy to complete, and the raters found them easy to administer. All tests had good inter-rater reliability, and the composite score had very high test-retest reliability (ICC = 0.91). One-factor structure better represented the data with excellent internal consistency (α = .81). ECAS significantly differentiated PWS from controls with 77% sensitivity and 62% specificity at a Z-score ≤0.12 cut-off value. IRT analysis suggested that the battery functions best among moderately impaired participants (difficulty between -0.06 and 0.66). ECAS is a practical, tolerable, reliable, and valid assessment of cognition. ECAS can supplement current assessment tools in LAMICs for PWS and can be used to measure cognitive intervention outcomes.

Depression severity mediates stigma and quality of life in clinically stable people with schizophrenia in rural China

BackgroundDepressive symptoms associated with schizophrenia are closely related to stigma and quality of life(QOL). There is, however, no thorough research on the connection between the three. This study sought to investigate the possible factors influencing depressive symptoms in people with schizophrenia (PWS) in rural Chaohu, China, and to further explore the role of depression severity in stigma and lifestyle quality.MethodsEight hundred twenty-one schizophrenia patients accomplished the entire scale, including the 9-item Patient Health Questionnaire (PHQ-9), the Social Impact Scale (SIS), and the World Health Organization on Quality of Life Brief Scale(WHOQOL—BREF). A straightforward mediation model was employed to determine if the intensity of the depression could act as a mediator between stigma and QOL.ResultsTwo hundred seventy-nine schizophrenia patients (34%) had depressive symptoms (PHQ ≥ 10), and 542 patients (66%) did not (PHQ < 10). Logistic regression showed that marital status, job status, physical exercise, standard of living, and stigma contributed to the depressed symptoms of schizophrenia. Depression severity partially mediated the effect between stigma and QOL, with a mediating effect of 48.3%.ConclusionsThis study discovered a significant incidence of depressed symptoms associated with schizophrenia, with depression severity serving as a mediator variable connecting stigma and QOL and partially moderating the association.

Executive functioning trajectories and their prospective association with inflammatory biomarkers in schizophrenia and non-psychiatric comparison participants

Background and hypothesisCognitive change in people with schizophrenia (PwS) is challenging to assess, but important to understand. Previous studies with limited age ranges and follow-up were subject to practice effects. Controlling for practice effects in a well-established cohort, we examined executive functioning trajectories and their association with inflammatory biomarkers, hypothesizing that PwS will have worsening executive functioning over time compared to non-psychiatric comparison participants (NCs), predicted by higher baseline inflammation with a stronger relationship in PwS than NCs. Study designExecutive functioning was assessed in 350 participants (n = 186 PwS, 164 NCs) at 12–16-month intervals (0 to 7 follow-up visits). Inflammatory biomarkers at baseline included high sensitivity C-Reactive Protein (hs-CRP), Interferon-gamma, Tumor Necrosis Factor (TNF)-alpha, and Interleukin(IL)-6, −8, and − 10. Executive functioning trajectories across diagnostic groups were estimated using a linear mixed-effects model controlling for age, sex, race/ethnicity, and education level, with additional models to assess prediction by baseline inflammation. Study resultsOver 4.4 years average follow-up, improvements in executive functioning were attenuated in PwS and older participants. Controlling for practice effects negated improvements, revealing declines among highly educated participants regardless of diagnosis. Higher baseline hs-CRP predicted worse executive functioning only among NCs, while TNF-alpha was predictive of change in all participants only after controlling for practice effects. Only the main effect of hs-CRP on executive function was significant after adjusting for multiple comparisons. None of the other inflammatory biomarkers predicted executive functioning or trajectories of performance among study participants. ConclusionsSystemic inflammation as reflected by baseline inflammatory biomarker levels did not predict longitudinal declines in executive functioning. Additional studies examining the temporal dynamics of inflammation and cognition in PwS will help further clarify their relationship and associated mechanisms.

Introducing an interview-based cognitive assessment tool for people with Schizophrenia in Ethiopia

Assessment of cognitive impairment in people with schizophrenia (PWS) is limited in low and middle-income countries due to lack of context-appropriate measures. This study aimed to select, adapt, and evaluate an interview-based cognitive tool for PWS in Ethiopia. The study was carried out in three phases. In the first phase, we followed a rigorous instrument selection procedure to select a tool for adaptation. We then applied a rigorous instrument adaption procedure, including interviews with 24 participants. Finally, we evaluated the psychometric properties of the adapted tool with 208 PWS and 208 matched controls. The Cognitive Assessment Interview was selected as the appropriate tool for adaptation. This tool is practical and tolerable, with short time of administration. We reported high inter-rater reliability and test-retest reliability for the adapted scale. One-factor structure better represented the data with excellent internal consistency. Weak but significant correlation with a performance-based battery was reported. At a cut-off value of > 13, the tool significantly differentiated PWS from controls (62 % sensitivity and 82 % specificity). Item Response Theory-based analysis showed that the tool gives much information among severely impaired participants. The findings show that the tool is reliable, valid, and practical in resource-scarce settings.

Qualitatively Different Delay-Dependent Working Memory Distortions in People With Schizophrenia and Healthy Control Participants

BackgroundImpairments in working memory (WM) have been well documented in people with schizophrenia (PSZ). However, these quantitative WM impairments can often be explained by nonspecific factors, such as impaired goal maintenance. Here, we used a spatial orientation delayed response task to explore a qualitative difference in WM dynamics between PSZ and healthy control participants (HCs). More specifically, we took advantage of the discovery that WM representations may drift either toward or away from previous trial targets (serial dependence). We tested the hypothesis that WM representations would drift toward the previous trial target in HCs but away from the previous trial target in PSZ. MethodsWe assessed serial dependence in PSZ (n = 31) and HCs (n = 25) using orientation as the to-be-remembered feature and memory delays lasting from 0 to 8 seconds. Participants were asked to remember the orientation of a teardrop-shaped object and reproduce the orientation after a delay period of varying length. ResultsConsistent with prior studies, we found that current trial memory representations were less precise in PSZ than in HCs. We also found that WM for the current trial orientation drifted toward the previous trial orientation in HCs (representational attraction) but drifted away from the previous trial orientation in PSZ (representational repulsion). ConclusionsThese results demonstrate a qualitative difference in WM dynamics between PSZ and HCs that cannot be easily explained by nuisance factors such as reduced effort. Most computational neuroscience models also fail to explain these results because they maintain information solely by means of sustained neural firing, which does not extend across trials. The results suggest a fundamental difference between PSZ and HCs in longer-term memory mechanisms that persist across trials, such as short-term potentiation and neuronal adaptation.

Effectiveness of a Therapeutic Educational Oral Health Program for Persons with Schizophrenia: A Cluster Randomized Controlled Trial and Qualitative Approach.

The oral health of people with schizophrenia (PWS) is very poor, suggesting a need for oral health promotion programmes with a high level of evidence. The aim of the EBENE study (Clinicaltrials.gov: NCT02512367) was to develop and evaluate the effectiveness of a multidisciplinary therapeutic educational programme in oral health (TEPOH) for PWS. A multicentre cluster randomised controlled trial, with outpatient psychiatry centres as the unit of randomisation, was designed to compare the effectiveness of TEPOH (intervention group) versus standard care (control group). The trial was conducted in 26 outpatient psychiatry centres in France (14 in the intervention group, 12 in the control group). Eligible patients with a diagnosis of schizophrenia were enroled between 2016 and 2020 and followed for 6 months. The TEPOH group received a multicomponent intervention (comprising an introductory session, three educational sessions, and a debriefing session). The primary endpoint was the evaluation of periodontal disease as a community periodontal index (CPI) score ≥ 3 at Month 6. The trial was completed using a qualitative approach based on semi-structured interviews with caregivers conducted between July 2018 and December 2019. The trial was stopped early due to difficulties in recruiting patients. Overall, 81 patients (of 250 planned) were included, and 54 patients completed the trial: 40 in the TEPOH group and 14 in the control group. At baseline, the percentage of CPI ≥ 3 was 42.5% in the TEPOH group and 9.1% in the control group. At Month 6, the percentage of CPI ≥ 3 was 20% in the TEPOH group and 14.3% in the control group. The qualitative evaluation underlined that the professionals emphasised the "seriousness" and "assiduity" of the patients' participation in this programme and that the TEPOH reinforced carers' investment in oral hygiene. It also highlighted structural factors (lack of resources for professionals, lack of teeth in PWS, COVID-19 pandemic) that may have exacerbated the difficulties with enrolment and follow-up. The effectiveness of this TEPOH, developed for PWS as part of the EBENE study, has not been demonstrated. Certain aspects of the programme's content and implementation need to be reconsidered. In particular, an adapted subjective measurement scale should be developed.

Reducing College Student's Stigma Toward People With Schizophrenia: A Pilot Trial

Purpose: A new 1-day intervention grounded on the inter-group contact theory was developed and implemented to reduce college students’ stigma toward people with schizophrenia (PWS). We hypothesized that the stigmatizing situation could be alleviated by different levels of contact. Method: A pilot trial was conducted in Hong Kong with 41 college students participating in the intervention. Participants’ perception, stigmatizing attitudes, and social distance toward PWS were measured pre-, post, and 1-month after the intervention. Results: Significant changes were found in all outcome variables with moderate to high effect sizes. Knowledge session without direct contact contributed most to participants’ knowledge improvement, and higher levels of contact led to an obvious improvement in stigmatizing attitudes and social distance changes. Discussion:The current study provided evidence supporting the efficacy of the new intervention based on inter-group contact theory and practical experience for future stigma research.

Phenomenological and Cognitive Features Associated With Auditory Hallucinations in Clinical and Nonclinical Voice Hearers.

Auditory verbal hallucinations (AVH) are central features of schizophrenia (SZ). However, AVH also occur in a small percentage of the general population who do not have a need for care, termed nonclinical voice hearers (NCVH). We sought to determine the degree to which the experience of AVH was similar in NCVH and in people with schizophrenia (PSZ) and evaluate the degree to which NCVH shared other features of SZ such as delusional beliefs, cognitive impairment, and negative symptoms. We recruited 76 people with a DSM-V diagnosis of SZ/schizoaffective disorder (PSZ; 49 with current AVH, 27 without), 48 NCVH, and 51 healthy controls. Participants received a broad battery of clinician-administered and self-report symptom assessments and a focused cognitive assessment. The AVH of NCVH and PSZ shared very similar sensory features. NCVH experienced less distress, had greater control over their AVH, and, unlike PSZ, rarely heard 2 voices speaking to each other. NCVH demonstrated a wide range of deeply held unusual beliefs, but reported less paranoia, and fewer first-rank symptoms such as passivity and alterations in self-experience. NCVH showed no evidence of cognitive deficits or negative symptoms. The AVH in NCVH and PSZ demonstrate important similarities as well as clear differences. Specific features, rather than the presence, of AVH appear to determine the need for care. NCVH do not share the cognitive and motivational deficits seen in PSZ. These results suggest that AVH and unusual beliefs can be separated from the broader phenotype of SZ.

Prefrontal activation during simulated driving in people with schizophrenia: A functional near-infrared spectroscopy study

People with schizophrenia (PWS) could be at risk when driving, yet this remains to be confirmed. In this study, we used functional near-infrared spectroscopy (fNIRS) and a driving simulator to assess potential driving skill difficulties as reflected by brain activity in PWS and compared them with those of healthy controls (HCs). Twenty PWS and 20 HCs were evaluated. Four tasks were performed: 50-kph and 100-kph sudden braking and 50-kph left and right curve tasks. The hemodynamic activity and driving performance of the two groups were compared. No significant differences were found in the performance of the four tasks. However, significant differences in hemodynamic activity were observed in the left and right dorsolateral prefrontal cortex (DLPFC) during the 100-kph sudden braking task. In addition, a significant negative correlation was found between brake reaction time and brain activity in the left DLPFC during the 100-kph sudden braking task in both groups. The brain mechanisms involved in processing the mental load associated with driving a car are possibly similar in PWS and HCs. Our results suggest that PWS may be able to drive their vehicles safely in the community.

Sustained attention deficits in schizophrenia: Effect of memory load on the Identical Pairs Continuous Performance Test

BackgroundSustained attention and vigilance impairments are well documented in people with schizophrenia (PSZ). The processes implicated in this impairment remain unclear. Here we investigated whether vigilance performance varied as a function of working memory load, and also examined the role of attentional lapsing that might arise from a loss of task set resulting in mind wandering. MethodWe examined Continuous Performance Test Identical Pairs (CPT-IP) data from a cumulative sample of 247 (PSZ) and 238 healthy control (HC) participants collected over a series of studies. ResultsPSZ performed more poorly that HC across conditions with signal/noise discrimination (d′) decreasing with increasing working memory load across both groups However, there was a significant interaction of group and load suggesting that performance of PSZ was more negatively impacted by increasing load. We also found that PSZ has a significantly higher rate of attention lapsing than did HC. DiscussionOur results suggest that difficulties maintaining task set and working memory limitations are implicated in the impairments observed on the Identical Pairs CPT. Difficulties with task set maintenance appear to explain the majority of between-group variance, with a more subtle impact of increasing working memory load.