Group Of Schizophrenia Patients Research Articles

The mesolimbic system and the loss of higher order network features in schizophrenia when learning without reward.

Schizophrenia is characterized by a loss of network features between cognition and reward sub-circuits (notably involving the mesolimbic system), and this loss may explain deficits in learning and cognition. Learning in schizophrenia has typically been studied with tasks that include reward related contingencies, but recent theoretical models have argued that a loss of network features should be seen even when learning without reward. We tested this model using a learning paradigm that required participants to learn without reward or feedback. We used a novel method for capturing higher order network features, to demonstrate that the mesolimbic system is heavily implicated in the loss of network features in schizophrenia, even when learning without reward. fMRI data (Siemens Verio 3T) were acquired in a group of schizophrenia patients and controls (n=78; 46 SCZ, 18 ≤ Age ≤ 50) while participants engaged in associative learning without reward-related contingencies. The task was divided into task-active conditions for encoding (of associations) and cued-retrieval (where the cue was to be used to retrieve the associated memoranda). No feedback was provided during retrieval. From the fMRI time series data, network features were defined as follows: First, for each condition of the task, we estimated 2nd order undirected functional connectivity for each participant (uFC, based on zero lag correlations between all pairs of regions). These conventional 2nd order features represent the task/condition evoked synchronization of activity between pairs of brain regions. Next, in each of the patient and control groups, the statistical relationship between all possible pairs of 2nd order features were computed. These higher order features represent the consistency between all possible pairs of 2nd order features in that group and embed within them the contributions of individual regions to such group structure. From the identified inter-group differences (SCZ ≠ HC) in higher order features, we quantified the respective contributions of individual brain regions. Two principal effects emerged: 1) SCZ were characterized by a massive loss of higher order features during multiple task conditions (encoding and retrieval of associations). 2) Nodes in the mesolimbic system were over-represented in the loss of higher order features in SCZ, and notably so during retrieval. Our analytical goals were linked to a recent circuit-based integrative model which argued that synergy between learning and reward circuits is lost in schizophrenia. The model's notable prediction was that such a loss would be observed even when patients learned without reward. Our results provide substantial support for these predictions where we observed a loss of network features between the brain's sub-circuits for a) learning (including the hippocampus and prefrontal cortex) and b) reward processing (specifically constituents of the mesolimbic system that included the ventral tegmental area and the nucleus accumbens. Our findings motivate a renewed appraisal of the relationship between reward and cognition in schizophrenia and we discuss their relevance for putative behavioral interventions.

Alpha peak frequency affects visual performance beyond temporal resolution

Abstract Recent work suggests that the individual alpha peak frequency (IAPF) reflects the temporal resolution of visual processing: individuals with higher IAPF can segregate stimuli at shorter intervals compared to those with lower IAPF. However, this evidence mainly comes from studies focusing on short intervals, with stimulus onset asynchronies (SOA) rarely extending beyond a single alpha cycle (e.g., ~100 ms). Here, we investigated the relationship between IAPF and performance in visual backward masking (VBM), which allowed us to test the effects of IAPF for longer SOAs than an alpha cycle. A group of healthy controls (N = 79) and schizophrenia patients (N = 121), who generally exhibit lower IAPF, were tested in conditions with a Vernier shown alone, a Vernier followed by a mask at two SOAs (30 and 150 ms), or only a mask. Our results show that IAPF can predict VBM performance in all conditions with a Vernier. Furthermore, in both the control and schizophrenia groups, individuals with higher IAPF showed reduced masking effects, even when the SOA of 150 ms exceeded the alpha cycle. These findings challenge the notion that IAPF is exclusively related to temporal resolution and visual processing within a single alpha cycle. We discuss alternative mechanisms by which IAPF determines visual performance.

Patients with first-episode psychosis in northern Taiwan: neurocognitive performance and niacin response profile in comparison with schizophrenia patients of different familial loadings and relationship with clinical features

BackgroundExamining patients with first-episode psychosis (FEP) provides opportunities to better understand the mechanism underlying these illnesses. By incorporating quantitative measures in FEP patients, we aimed to (1) determine the baseline distribution of clinical features; (2) examine the impairment magnitude of the quantitative measures by comparing with external controls and then the counterparts of schizophrenia patients of different familial loadings; and (3) evaluate whether these quantitative measures were associated with the baseline clinical features.MethodsPatients with FEP were recruited from one medical center, two regional psychiatric centers, and two private clinics in northern Taiwan with clinical features rated using the Positive and Negative Syndrome Scale (PANSS) and Personal and Social Performance (PSP) scale. Quantitative measurements included the Continuous Performance Test (CPT), Wisconsin Card Sorting Test (WCST), niacin response abnormality (NRA), and minor physical anomalies and craniofacial features (MPAs). To evaluate the relative performance of the quantitative measures in our FEP patients, four external comparison groups from previous studies were used, including three independent healthy controls for the CPT, WCST, and NRA, respectively, and one group of treatment-resistant schizophrenia patients for the MPAs. Additionally, patients from simplex families and patients from multiplex families were used to assess the magnitude of FEP patients’ impairment on the CPT, WCST, and NRA.ResultsAmong the 80 patients with FEP recruited in this study (58% female, mean age = 25.6 years, mean duration of untreated psychosis = 132 days), the clinical severity was mild to moderate (mean PANSS score = 67.3; mean PSP score = 61.8). Patients exhibited both neurocognitive and niacin response impairments (mean Z-scores: −1.24 for NRA, − 1.06 for undegraded d', − 0.70 for degraded d', − 0.32 for categories achieved, and 0.44 for perseverative errors) but did not show MPAs indicative of treatment resistance. Among these quantitative measures, three of the four neurocognitive indices were correlated with the baseline clinical features, whereas NRA did not show such correlation.ConclusionsThis FEP study of Taiwanese patients revealed the presence of neurocognitive performance and niacin response and their different relationships with clinical features, rendering this sample useful for future follow-up and incorporation of multiomics investigation.

Differentiation of the retinal morphology aging trajectories in schizophrenia and their associations with cognitive dysfunctions.

Previous studies evaluating the morphology of the selected retinal layers in schizophrenia showed abnormalities regarding macular thickness, retinal nerve fiber layer (RNLF), and ganglion cell complex (GCC). Concurrently, accumulating neuroimaging results suggest that structural alterations of the brain in this disease might be an effect of accelerated aging. Referring to these findings, we aimed to determine whether the thinning of the retinal layers assessed with the optic coherence tomography (OCT) in a group of schizophrenia patients (n = 60) presents a significant age-related decrease exceeding potential changes noted in the control group (n = 61). Samples of patients and controls were divided into three age subgroups, namely, younger, middle-aged, and older participants. OCT outcomes, such as macular thickness and volume, macular RNFL, peripapillary RNFL, and GCC, were analyzed concerning a diagnosis status (controls vs. patients) and age subgroups. Additionally, associations between retinal parameters, age, and selected cognitive functions were evaluated. post-hoc tests revealed that macular thickness and volume in patients undergo significant age-dependent thinning, which was not observed in the control group. Regression analyses confirmed the association between macular morphology and age. Selected speed-dependent cognitive functions in patients decreased significantly with age, and these features were also significantly associated with some OCT outcomes also after controlling for antipsychotic treatment. Our results suggest that reduced measures of retinal structure detected in schizophrenia may be an effect of accelerated aging; however, further research is needed using computational solutions derived from brain imaging studies based on large datasets covering representatives of all age groups.

Do the negative symptoms of schizophrenia reflect reduced responsiveness to reward? Examination using a reward prediction error (RPE) task.

A leading theory of the negative symptoms of schizophrenia is that they reflect reduced responsiveness to rewarding stimuli. This proposal has been linked to abnormal (reduced) dopamine function in the disorder, because phasic release of dopamine is known to code for reward prediction error (RPE). Nevertheless, few functional imaging studies have examined if patients with negative symptoms show reduced RPE-associated activations. Matched groups of DSM-5 schizophrenia patients with high negative symptom scores (HNS, N = 27) or absent negative symptoms (ANS, N = 27) and healthy controls (HC, N = 30) underwent fMRI scanning while they performed a probabilistic monetary reward task designed to generate a measure of RPE. In the HC, whole-brain analysis revealed that RPE was positively associated with activation in the ventral striatum, the putamen, and areas of the lateral prefrontal cortex and orbitofrontal cortex, among other regions. Group comparison revealed no activation differences between the healthy controls and the ANS patients. However, compared to the ANS patients, the HNS patients showed regions of significantly reduced activation in the left ventrolateral and dorsolateral prefrontal cortex, and in the right lingual and fusiform gyrus. HNS and ANS patients showed no activation differences in ventral striatal or midbrain regions-of-interest (ROIs), but the HNS patients showed reduced activation in a left orbitofrontal cortex ROI. The findings do not suggest that a generalized reduction of RPE signalling underlies negative symptoms. Instead, they point to a more circumscribed dysfunction in the lateral frontal and possibly the orbitofrontal cortex.

Alcohol related cognitive impairments in schizophrenia patients : A case-control study

IntroductionCognitive impairment is a well-recognized key feature of schizophrenia. However, these cognitive impairments may be worsened by alcohol consumption. Up to 80% of patients with alcohol use disorders (AUD) display cognitive impairments. Screening for those impairments with a full neuropsychological assessment may be difficult. The Brief Evaluation Alcohol-Related Neuropsychological Impairments (BEARNI) is a specific tool for screening those impairments easy to implement in in clinical practice (Ritz et al. Alcoholism: Clinical and Experimental Research 2015; 39, 2249-60). To our knowledge, no previous studies have assessed the alcohol-related cognitive impairments using the BEARNI test in schizophrenia patients.ObjectivesThe objective of the study was to compare BEARNI mean scores between a group of schizophrenia patients with alcohol use disorders and a group of schizophrenia patients without alcohol use disorder.Methods39 patients with schizophrenia and AUD (SCZ/AUD +) (82% males, mean age 44.9 ± 11.0 years-old) and 49 patients with schizophrenia without AUD (SCZ/AUD-) (65% males, mean age 42.6 ± 11.4 years-old) consecutively included in the study, were assessed using the BEARNI test. All patients met DSM-5 criteria for schizophrenia and AUD. Demographic and clinical variables were also collected, using the Alcohol Use Disorders Identification Test (AUDIT) and the Positive and Negative Syndrome Scale (PANSS). The primary endpoint of the study was the difference in BEARNI cognitive mean scores between the SCZ/AUD+ and SCZ/AUD- groups.ResultsThere was no difference between the two groups regarding demographic variables or PANSS mean scores (59.1 ± 12.8 vs 58.1 ± 14.0; t=-0.3; p=0.7). The AUDIT mean score was higher in the group of patients SCZ/AUD+ (20.6 ± 7.8 vs 1.6 ± 1.5; t=-14.7; p<0.0001). Total BEARNI and cognitive BEARNI mean scores were significantly lower in the group of patients SCZ/AUD+ compared to the group of patients SCZ/AUD- (10.6 ± 4.8 vs 12.6 ± 5.2; t=1.8, p=0.03 and 8.1 ± 3.9 vs 9.8 ± 3.6 t=2.0, p=0.04, respectively). The mean subscores of delayed verbal memory, alphabetical ordination, and alternating verbal fluency subtests were also significantly lower in the group of patients SCZ/+ group (respectively 1,0 ± 0.9 vs 1.6 ± 1.2, t= 2.5, p=0.01; 2,1 ± 1.2 vs 2.5 ± 1.1, t= 1.6, p=0.04; 3.3 ±1.5 vs 3.8 ± 1.5, t= 1.8, p=0.03).ConclusionsThe present study found cognitive impairments using BEARNI test in schizophrenia patients with AUD compared to their counterparts without AUD. Screening alcohol related cognitive impairments using BEARNI could be easier in patients in schizophrenia patients with AUD than usual neurocognitive assessmentsDisclosure of InterestNone Declared

The influence of substance abuse on inhibition capacities and risky decision in a group of outpatient schizophrenia patients

IntroductionSubstance abuse is common among patients with schizophrenia, is related toworse course and outcome of illness. Unfortunately, little is known about how substanceabuse affects the cognitive function of schizophrenia patients, whose cognitive function isoften already comprised. Neurocognitive functioning includes inhibition control and decision-making, and both schizophrenia and substance use disorder are related to impairmentsof inhibition control. However, the influence of substance abuse on inhibition capacitiesamong schizophrenia patients is unclearObjectivesThis study measured the influence of substance use disorder on inhibition capacities and risky decision-making in a group of 39 schizophrenia patients that were evaluated using a socio-demographic questionnaire and clinical assessment using the Positive and Negative Syndromes Scale for Schizophrenia. To assess inhibition control we utilized the Matching Familiar Figure Test (MFFT) and the Stroop task, and to evaluate decision-making we used the Iowa Gambling Task (IGT) and self-report questionnaire, the Barratt Impulsiveness ScaleMethodsUnivariate analysis found significant differences between the groups with regard to criminal history (v2¼5.97, p¼.015), smoking status (v:12.30, p<.001), and total BIS score (t: 2.69, df¼37, p¼.01). Our model did not find a significant effect of substance abuse on the first response time and number of errors on the MFFT or in the total interference index of Stroop performance and net score on risky decision-making in the IGT.ResultsThe two groups did not differ significantly either in first response time or in number of errors on the MFFT (F¼0.54, p¼.47, d¼0.24, 95% CI [-0.4, 0.88]; F¼0.28, p¼.60, d¼0.61, 95% CI [0, 1.26], respectively), nor did they differ in the total interference index of the Stroop task (F(1)¼0.49, p¼.49, d¼0.25, 95% CI [-0.38, 0.88]).ConclusionsThe analyses did not detect any statistically significant effect of substance abuse on inhibition control or risky decision-making processes in outpatients diagnosed with schizophrenia, despite increased impulsivity, criminal history and smoking status. These results neither support nor disprove previous findings.Disclosure of InterestNone Declared

Examining Factors Associated with Dynapenia/Sarcopenia in Patients with Schizophrenia: A Pilot Case-Control Study.

Sedentary behavior in patients with schizophrenia causes muscle weakness, is associated with a higher risk of metabolic syndrome, and contributes to mortality risk. This pilot case-control study aims to examine the associated factors for dynapenia/sarcopenia in patients with schizophrenia. The participants were 30 healthy individuals (healthy group) and 30 patients with schizophrenia (patient group), who were matched for age and sex. Descriptive statistics, Welch's t-test, cross-tabulations, adjusted residuals, Fisher's exact probability test (extended), and/or odds ratios (ORs) were calculated. In this study, dynapenia was significantly more prevalent in patients with schizophrenia than in healthy individuals. Regarding body water, Pearson's chi-square value was 4.41 (p = 0.04), and significantly more patients with dynapenia were below the normal range. In particular, body water and dynapenia showed a significant association, with an OR = 3.42 and 95% confidence interval [1.06, 11.09]. Notably, compared with participants of the healthy group, patients with schizophrenia were overweight, had less body water, and were at a higher risk for dynapenia. The impedance method and the digital grip dynamometer used in this study were simple and useful tools for evaluating muscle quality. To improve health conditions for patients with schizophrenia, additional attention should be paid to muscle weakness, nutritional status, and physical rehabilitation.

Cross-Cultural Adaptation and Validation of the Serbian Version of the Brief Assessment of Cognition in Schizophrenia Scale.

The Brief Assessment of Cognition in Schizophrenia (BACS) scale was developed for the assessment of cognitive function in patients with schizophrenia. The objective of this study was to cross-culturally adapt and validate the BACS in to the Serbian language. The study was conducted at the Laza Lazarevic Clinic for Mental Disorders and the Clinic for Psychiatry of the University Clinical Center of Serbia from March 2021 to January 2022. The study enrolled 61 inpatients diagnosed with schizophrenia and 61 healthy controls matched for age and sex. Compared with the healthy control group, the schizophrenia patient group had worse cognitive function in all dimensions measured using BACS (p < 0.001 for all measures). The mean standardized composite BACS score was z = -2.46, and symbol coding (z = -2.54) was the most deficient function. Principal component analysis suggests a two-factor structure, where the first factor consisted of loading the measures of verbal and working memory, attention, speed of information processing, and executive function, while the second factor regarded the loading of motor speed. Cronbach's alpha coefficient demonstrated an excellent level of internal consistency (0.798). These outcomes suggest that the Serbian BACS neurocognitive battery's psychometric properties are satisfactory, with good overall discriminant validity and high internal consistency. The Serbian BACS appears to be a quick and reliable neuropsychological instrument for evaluating global cognition in schizophrenia patients in Serbia.

Impact of framing scheme optimization and smoking status on binding potential analysis in dynamic PET with [11C]ABP688

BackgroundFor positron emission tomography (PET) ligands, such as [11C]ABP688, to be able to provide more evidence about the glutamatergic hypothesis in schizophrenia (SZ), quantification bias during dynamic PET studies and its propagation into the estimated values of non-displaceable binding potential (BPND) must be addressed. This would enable more accurate quantification during bolus + infusion (BI) neuroreceptor studies and further our understanding of neurological diseases. Previous studies have shown BPND-related biases can often occur due to overestimated cerebellum activity (reference region). This work investigates whether an alternative framing scheme can minimize quantification biases propagated into BPND, whether confounders, such as smoking status, need to be controlled for during the study, and what the consequences for the data interpretation following analysis are. A group of healthy controls (HC) and a group of SZ patients (balanced and unbalanced number of smokers) were investigated with [11C]ABP688 and a BI protocol. Possible differences in BPND quantification as a function of smoking status were tested with constant 5 min (‘Const 5 min’) and constant true counts (‘Const Trues’) framing schemes. In order to find biomarkers for SZ, the differences in smoking effects were compared between groups. The normalized BPND and the balanced number of smokers and non-smokers for both framing schemes were evaluated.ResultsWhen applying F-tests to the ‘Const 5 min’ framing scheme, effect sizes (η2p) and brain regions which showed significant effects fluctuated considerably with F = 50.106 ± 54.948 (9.389 to 112.607), P-values 0.005 to < 0.001 and η2p = 0.514 ± 0.282 (0.238 to 0.801). Conversely, when the ‘Const Trues’ framing scheme was applied, the results showed much smaller fluctuations with F = 78.038 ± 8.975 (86.450 to 68.590), P < 0.001 for all conditions and η2p = 0.730 ± 0.017 (0.742 to 0.710), and regions with significant effects were more robustly reproduced. Further, differences, which would indicate false positive identifications between HC and SZ groups in five brain regions when using the ‘Const 5 min’ framing scheme, were not observed with the ‘Const Trues’ framing.ConclusionsBased on an [11C]ABP688 PET study in SZ patients, the results show that non-consistent BPND outcomes can be propagated by the framing scheme and that potential bias can be minimized using ‘Const Trues’ framing.

Comparison of Subjective Facial Emotion Recognition and "Facial Emotion Recognition Based on Multi-Task Cascaded Convolutional Network Face Detection" between Patients with Schizophrenia and Healthy Participants.

Patients with schizophrenia may exhibit a flat affect and poor facial expressions. This study aimed to compare subjective facial emotion recognition (FER) and FER based on multi-task cascaded convolutional network (MTCNN) face detection in 31 patients with schizophrenia (patient group) and 40 healthy participants (healthy participant group). A Pepper Robot was used to converse with the 71 aforementioned participants; these conversations were recorded on video. Subjective FER (assigned by medical experts based on video recordings) and FER based on MTCNN face detection was used to understand facial expressions during conversations. This study confirmed the discriminant accuracy of the FER based on MTCNN face detection. The analysis of the smiles of healthy participants revealed that the kappa coefficients of subjective FER (by six examiners) and FER based on MTCNN face detection concurred (κ = 0.63). The perfect agreement rate between the subjective FER (by three medical experts) and FER based on MTCNN face detection in the patient, and healthy participant groups were analyzed using Fisher's exact probability test where no significant difference was observed (p = 0.72). The validity and reliability were assessed by comparing the subjective FER and FER based on MTCNN face detection. The reliability coefficient of FER based on MTCNN face detection was low for both the patient and healthy participant groups.

Proactive and reactive cognitive control for emotional conflict in individuals with high schizotypy: An ERP study

ObjectiveThe present study aimed to examine how individuals with high schizotypy, a high risk group of schizophrenia patients, resolve emotional conflict in proactive and reactive control and the underlying neural mechanisms. MethodsThirty-two individuals with high schizotypy and 30 matched individuals with low schizotypy completed an emotional face–word Stroop task with electroencephalographic data recorded. The proportion of incongruent trials was manipulated in the task to induce proactive control (mostly incongruent trials context, MI context) or reactive control (mostly congruent trials context, MC context). Two event-related potential (ERP) components (N170 and N2) were examined, which represent face processing and cognitive control processes, respectively. ResultsIn the MC context, significantly decreased N2 and N170 amplitudes were found in high schizotypy individuals compared with low schizotypy individuals, suggesting abnormal neural activity of reactive control in high schizotypy individuals. No significant differences were found between the two groups in the MI context. ConclusionsThese results provide initial evidence for dissociation of neural activity of proactive and reactive control on emotional conflict in individuals with high schizotypy. SignificanceThe current findings provide important insight into the emotional conflict resolution in the schizophrenia spectrum.

Evaluation of the relationship between death anxiety and clinical features of the disease and functionality in patients with schizophrenia

AimThis study aimed to examine the relationship between death anxiety in schizophrenia patients and the clinical characteristics of the disease and its functionality. MethodThe study included 52 patients diagnosed with schizophrenia according to the DSM-5 diagnostic criteria and 52 healthy volunteers. Death anxiety scores were compared between the two groups using the Abdel-Khalek Death Anxiety Scale (ADAS). The functionality of the schizophrenia patients was evaluated with the Functional Remission of General Schizophrenia (FROGS) scale. ResultsThe mean ADAS total scores were statistically significantly higher in the schizophrenia patient group than in the control group. A low-level negative correlation was determined between the ADAS total points and the FROGS total points, the FROGS subscales of daily life skills and health. ConclusionThe results of this study showed higher death anxiety in schizophrenia patients than in the healthy control group. Patients with a higher level of functionality were determined to have a lower level of death anxiety. These results support our idea that interventions and therapeutic approaches to increase functionality in patients with schizophrenia can reduce their death anxiety. In order to reach more evident conclusions on this subject, prospective studies that deal with the causal relationship between death anxiety and functionality are needed.

Migration, Schizophrenia, and Crime: A Study From a Forensic Psychiatric Sample.

BackgroundThe association between mental health problems and crime in immigrants has attracted recent academic interest, with results suggesting that there were possible interactions between immigration, schizophrenia, and criminal behavior. However, very few studies have examined these interactions, especially in developing countries that have mass internal immigration. Therefore, this study sought to identify the associations between the sociodemographic, clinical, and criminal factors in migrants and non-migrants with schizophrenia who had been involved in criminal activities in China.MethodsForensic archives of suspects who had been referred for criminal responsibility assessments in the Sichuan West China Forensic Center from January 2015 to December 2019 were reviewed. The sociodemographic, and criminal activity information of the suspects were extracted, while the clinical and social function were measured by the Brief Psychiatric Rating Scale (BPRS) and Social Disability Screening Schedule (SDSS) based on the archives. A Chi-squared test, a T-test, a Mann-Whitney U test, and Multinomial logistic regression were employed for the statistical analysis.ResultsA total of 552 patients were reviewed and evaluated, 17.2% (n = 95) of which were migrants. The migrant patient group was younger than the non-migrant patient group. The BPRS and SDSS scores for the migrant patient group were lower than for the non-migrant patient group. The migrant patient group had more work experience and more had been employed at the time of the crime than the non-migrant patient group. The unemployed migrant patients were more likely to commit a property-related crime.ConclusionsCompared to the non-migrant schizophrenia patient group, the migrant patient group had less severe psychiatric symptoms and less social function impairments. Employment was an important factor in preventing criminality in patients with schizophrenia, especially for migrant patients. Vocational rehabilitation focuses on developing appropriate employment that can significantly assist in schizophrenia patient recovery, which in turn could reduce their chances of committing crime. Besides, reducing other obstacles to stigma, housing and health insurance would also be beneficial to crime reduction.

Brave New World: Harnessing the promise of biomarkers to help solve the epigenetic puzzle

The term "schizophrenia" should be used to refer to a group of neurodevelopmentally mediated cognitive disorders. Although these disorders may have different etiologies, the final causal pathway is characterized by a cognitive triad of (working memory, corollary discharge, and inhibition) deficits. Biomarkers can be used to lend insights regarding underlying pathophysiology, and lead to more precise definitions of schizophrenia subtypes. Use of endophenotypes (i.e., traitlike heritable markers of liability) that are specific to schizophrenia would aid us in our search for these biomarkers by providing a means to classify more homogeneous groups of schizophrenia patients.

Screening of ERBB4 SNP rs1026882 in a group of Schizophrenia patients and controls

Schizophrenia is a multifactorial psychiatric disorder which is affected by genetic, environmental, and several other factors. ERBB4 is a gene with polymorphic sites which reported to be associated with schizophrenia. In this prospective study, we have tested the association of schizophrenia with one of the single nucleotide polymorphisms (SNP) called rs1026882 in the ERBB4 gene. We have screened the genotypes of rs1026882 in a case group consisted of 96 schizophrenia patients and 100 healthy controls. All samples were collected from the population living in Malatya-Turkey. First, we compared the distributions of SNP genotypes and alleles between the case and control groups, then between the subgroups of patients defined according to SAPS and SANS parameters and phenotypical outcomes of the disease. Even though there was no significant difference between the case and control groups, comparing the subgroups of patients revealed that, the CC genotype was more common than the CT through the patients showing avolition-apathy symptom (one of the parameters in SANS). In addition, TT genotype was significantly more frequent in the subgroup of patients exhibiting the phenotype of suicidal thoughts.Our study was limited with a relatively small sample size and a population living in a small geographical region. Therefore, screening of rs1026882 genotypes in larger case-control groups from different populations is thought to help to reveal stronger evidence for presence of the association between this SNP and schizophrenia phenotypes. As conclusion, we did not find a direct association between rs1026882 genotype and schizophrenia in general, but the TT genotype was associated with the phenotype of suicidal thoughts, and the CC genotype seems related to avolition-apathy symptom in our sample.

Differential aberrant connectivity of precuneus and anterior insula may underpin the diagnosis of schizophrenia and mood disorders.

BACKGROUNDOver the past decade, resting-state functional magnetic resonance imaging (rs-fMRI) has concentrated on brain networks such as the default mode network (DMN), the salience network (SN), and the central executive network (CEN), allowing for a better understanding of cognitive deficits observed in mental disorders, as well as other characteristic psychopathological phenomena such as thought and behavior disorganization.AIMTo investigate differential patterns of effective connectivity across distributed brain networks involved in schizophrenia (SCH) and mood disorders. METHODSThe sample comprised 58 patients with either paranoid syndrome in the context of SCH (n = 26) or depressive syndrome (Ds) (n = 32), in the context of major depressive disorder or bipolar disorder. The methods used include rs-fMRI and subsequent dynamic causal modeling to determine the direction and strength of connections to and from various nodes in the DMN, SN and CEN.RESULTSA significant excitatory connection from the dorsal anterior cingulate cortex to the anterior insula (aI) was observed in the SCH patient group, whereas inhibitory connections from the precuneus to the ventrolateral prefrontal cortex and from the aI to the precuneus were observed in the Ds group. CONCLUSIONThe results delineate specific patterns associated with SCH and Ds and offer a better explanation of the underlying mechanisms of these disorders, and inform differential diagnosis and precise treatment targeting.

Toxoplasmosis Is More Frequent in Schizophrenia Patients Than in the General Population in Mexico and Is Not Associated with More Severe Course of Schizophrenia Measured with the Brief Psychiatric Rating Scale.

Toxoplasmosis is a disease, which was discovered in 1908, caused by the intracellular parasite Toxoplasma gondii. T. gondii infects neuronal, glial, and muscle cells, and chronic infections are characterized by the presence of cysts, in the brain and muscle cells, formed by bradyzoites. T. gondii is capable of synthesizing L-DOPA, a precursor of dopamine. Dopamine is a neurotransmitter that is key in the etiology of neuropsychological disorders such as schizophrenia. Previous studies have shown high levels of IgG Toxoplasma antibodies in schizophrenia patients. Many published studies show that the prevalence of toxoplasmosis is higher in schizophrenia patients. In this study, we aimed to identify the prevalence of Toxoplasma infection in patients with schizophrenia and the relationships between, sociodemographic factors and the Brief Psychiatric Rating Scale. A total of 27 schizophrenic patients were included and IgG anti-T. gondii was determined in serum samples by ELISA. The Brief Psychiatric Rating Scale, sociodemographic factors were associated with seropositivity. We found that the prevalence of Toxoplasma antibodies was 51.7%. In the Brief Psychiatric Rating Scale, statistical significant association (p = 0.024) was found in Item 13 which is related to motor retardation, however, the association turned non-significant after of correction for multiple tests or after of analyzed with a logistic regression p = 0.059, odds ratio (OR) = 2.316 with a 95% confidence interval [0.970 to 5.532]. Other association was not found between toxoplasmosis and others factors. The prevalence of toxoplasmosis on our population under study was significantly higher than that reported by general population or other group of Mexican schizophrenia patients.

Sex differences in the association between serum BDNF and cognitive impairment in schizophrenia patients using various antipsychotics

BackgroundCognitive impairment is one of the core symptoms of schizophrenia patients. There are often various differences in the efficacy of different antipsychotics in the treatment of cognitive impairment by sex. The purpose of this study was to explore whether there are gender differences in the association between serum BDNF levels and cognitive performance in patients with schizophrenia taking different antipsychotics. MethodsWe used Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess the cognitive function of three groups of schizophrenia patients (420 on clozapine, 183 on risperidone, 215 on typical antipsychotic drugs) and 467 healthy controls. Positive and Negative Syndrome Scale (PANSS) was used to assess schizophrenia symptoms of patients. Enzyme-Linked ImmunoSorbent Assay was used to measure serum brain-derived neurotrophic factor (BDNF) levels. ResultsAmong the patients taking clozapine and typical antipsychotic drugs, the RBANS total score, immediate memory, attention, and delayed memory subscores in females were higher than those in males (all p < 0.05). The RBANS total score and the delayed memory subscores in female patients taking risperidone were higher than those in male patients (all p < 0.05). Significant correlation between BDNF and cognition only existed in male patients taking clozapine, male patients taking risperidone, and male and female patients taking typical antipsychotic drugs (all p < 0.05). ConclusionRegardless of antipsychotic effect, the cognitive function of female patients is better compared to that of male patients. For male patients, the association between BDNF and cognitive performance exists in each medication group. For female patients, this significant association was only shown in the typical antipsychotic group, but not in the clozapine and risperidone groups.

The Influence of Substance Abuse on Inhibition Capacities and Risky Decision in a Group of Outpatient Schizophrenia Patients

Objective Substance abuse is common among patients with schizophrenia, is related to worse course and outcome of illness. Unfortunately, little is known about how substance abuse affects the cognitive function of schizophrenia patients, whose cognitive function is often already comprised. Neurocognitive functioning includes inhibition control and decision-making, and both schizophrenia and substance use disorder are related to impairments of inhibition control. However, the influence of substance abuse on inhibition capacities among schizophrenia patients is unclear. Methods: This study measured the influence of substance use disorder on inhibition capacities and risky decision-making in a group of 39 schizophrenia patients that were evaluated using a socio-demographic questionnaire and clinical assessment using the Positive and Negative Syndromes Scale for Schizophrenia. To assess inhibition control we utilized the Matching Familiar Figure Test (MFFT) and the Stroop task, and to evaluate decision-making we used the Iowa Gambling Task (IGT) and self-report questionnaire, the Barratt Impulsiveness Scale. Results: Univariate analysis found significant differences between the groups with regard to criminal history (χ2 = 5.97, p=.015), smoking status (χ2 = 12.30, p<.001), and total BIS score (t= −2.69, df = 37, p=.01). Our model did not find a significant effect of substance abuse on the first response time and number of errors on the MFFT or in the total interference index of Stroop performance and net score on risky decision-making in the IGT. The two groups did not differ significantly either in first response time or in number of errors on the MFFT (F = 0.54, p=.47, d = 0.24, 95% CI [-0.4, 0.88]; F = 0.28, p=.60, d = 0.61, 95% CI [0, 1.26], respectively), nor did they differ in the total interference index of the Stroop task (F(1)=0.49, p=.49, d = 0.25, 95% CI [-0.38, 0.88]). Conclusion: The analyses did not detect any statistically significant effect of substance abuse on inhibition control or risky decision-making processes in outpatients diagnosed with schizophrenia, despite increased impulsivity, criminal history and smoking status. These results neither support nor disprove previous findings.