Evaluation of the factor structure of symptoms in patients with schizophrenia

Dissociable Default Mode Network Connectivity Patterns Underlie Distinct Symptoms in Psychosis Risk

The Clinical High Risk (CHR) stage of psychosis is characterized by subthreshold symptoms of schizophrenia including negative symptoms, dysphoric mood, and functional deterioration. Hyperconnectivity of the default-mode network (DMN) has been observed in early schizophrenia, but the extent to which hyperconnectivity is present in CHR, and the extent to which such hyperconnectivity may underlie transdiagnostic symptoms, is not clear. As part of the Shanghai At-Risk for Psychosis (SHARP) program, resting-state fMRI data were collected from 251 young adults (158 CHR and 93 controls, M = 18.72, SD = 4.68, 129 male). We examined functional connectivity of the DMN by performing a whole-brain seed-to-voxel analysis with the MPFC as the seed. Symptom severity across a number of dimensions, including negative symptoms, positive symptoms, and affective symptoms were assessed. Compared to controls, CHRs exhibited significantly greater functional connectivity (p < 0.001 uncorrected) between the MPFC and 1) other DMN nodes including the posterior cingulate cortex (PCC), and 2) auditory cortices (superior and middle temporal gyri, STG/MTG). Furthermore, these two patterns of hyperconnectivity were differentially associated with distinct symptom clusters. Within CHR, MPFC-PCC connectivity was significantly correlated with anxiety (r= 0.23, p=0.006), while MPFC-STG/MTG connectivity was significantly correlated with negative symptom severity (r=0.26, p=0.001). Secondary analyses using item-level symptom scores confirmed a similar dissociation. These results demonstrate that two dissociable patterns of DMN hyperconnectivity found in the CHR stage may underlie distinct dimensions of symptomatology.

Prevalence of metabolic syndrome and its associated factors in first-treatment drug-naïve schizophrenia patients: A large-scale cross-sectional study

BACKGROUND

Metabolic syndrome (MetS), a condition that includes several risk factors specific for cardiovascular disease, is commonly detected among patients with schizophrenia (SCZ). This study elucidated the factors contributing to the development and severity of MetS in first-treatment drug-naïve (FTDN) patients with SCZ.

METHODS

The study enrolled 668 individuals with FTDN SCZ, aged 18-49 years, who had no exposure to antipsychotic medications and been hospitalized between February 2017 and June 2022 at the largest psychiatric specialty institution in central China. Patient sociodemographic and general clinical data were collected, and their psychopathology scores and illness severity were assessed using the Positive and Negative Symptom Scale (PANSS) and Clinical Global Impression Scale-Severity of Illness (CGI-SI), respectively. MetS score was calculated to determine the disease severity.

RESULTS

The prevalence of MetS among this study population was 10.93%. Binary logistic regression analysis revealed onset age, female sex, total cholesterol, and red blood and white blood cell counts as risk factors for MetS, and deemed free tetraiodothyronine (FT4) and CGI-SI score as protective factors. Multiple linear regression analysis result confirmed older SCZ onset age as a risk factor for elevated MetS score.

CONCLUSION

This study determined the prevalence of MetS in patients with FTDN SCZ and revealed the factors that influence the occurrence and severity of the disease. These findings will allow development of specific prevention and treatment strategies in clinical practice.

Right superior frontal gyrus: A potential neuroimaging biomarker for predicting short-term efficacy in schizophrenia

Antipsychotic drug treatment for schizophrenia (SZ) can alter brain structure and function, but it is unclear if specific regional changes are associated with treatment outcome. Therefore, we examined the effects of antipsychotic drug treatment on regional grey matter (GM) density, white matter (WM) density, and functional connectivity (FC) as well as associations between regional changes and treatment efficacy. SZ patients (n = 163) and health controls (HCs) (n = 131) were examined by structural magnetic resonance imaging (sMRI) at baseline, and a subset of SZ patients (n = 77) were re-examined after 8 weeks of second-generation antipsychotic treatment to assess changes in regional GM and WM density. In addition, 88 SZ patients and 81 HCs were examined by resting-state functional MRI (rs-fMRI) at baseline and the patients were re-examined post-treatment to examine FC changes. The Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB) were applied to measure psychiatric symptoms and cognitive impairments in SZ. SZ patients were then stratified into response and non-response groups according to PANSS score change (≥50 % decrease or <50 % decrease, respectively). The GM density of the right cingulate gyrus, WM density of the right superior frontal gyrus (SFG) plus 5 other WM tracts were reduced in the response group compared to the non-response group. The FC values between the right anterior cingulate and paracingulate gyrus and left thalamus were reduced in the entire SZ group (n = 88) after treatment, while FC between the right inferior temporal gyrus (ITG) and right medial superior frontal gyrus (SFGmed) was increased in the response group. There were no significant changes in regional FC among the non-response group after treatment and no correlations with symptom or cognition test scores. These findings suggest that the right SFG is a critical target of antipsychotic drugs and that WM density and FC alterations within this region could be used as potential indicators in predicting the treatment outcome of antipsychotics of SZ.

Abnormalities of Regional Brain Activity in Patients With Schizophrenia: A Longitudinal Resting-State fMRI Study

BACKGROUND

Evidence from functional and structural research suggests that abnormal brain activity plays an important role in the pathophysiology of schizophrenia (SZ). However, limited studies have focused on post-treatment changes, and current conclusions are inconsistent.

STUDY DESIGN

We recruited 104 SZ patients to have resting-state functional magnetic resonance imaging scans at baseline and 8 weeks of treatment with second-generation antipsychotics, along with baseline scanning of 86 healthy controls (HCs) for comparison purposes. Individual regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and degree centrality values were calculated to evaluate the functional activity. The Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery were applied to measure psychiatric symptoms and cognitive impairment in SZ patients.

RESULTS

Compared with HCs at baseline, SZ patients had higher ALFF and ReHo values in the bilateral inferior temporal gyrus, inferior frontal gyrus, and lower ALFF and ReHo values in fusiform gyrus and precuneus. Following 8 weeks of treatment, ReHo was increased in right medial region of the superior frontal gyrus (SFGmed) and decreased in the left middle occipital gyrus and the left postcentral gyrus. Meanwhile, ReHo of the right SFGmed was increased after treatment in the response group (the reduction rate of PANSS ≥50%). Enhanced ALFF in the dorsolateral of SFG correlated with improvement in depressive factor score.

CONCLUSIONS

These findings provide novel evidence for the abnormal functional activity hypothesis of SZ, suggesting that abnormality of right SFGmed can be used as a biomarker of treatment response in SZ.

Gender differences in prevalence and associated factors of metabolic syndrome in first-treatment and drug-naïve schizophrenia patients

BACKGROUND

Metabolic syndromes (MetS) are clinical syndromes involving multiple pathological states with distinct gender-specific clinical patterns. As a serious disorder associated with psychiatric conditions, the prevalence of MetS is significantly higher in the population with schizophrenia (Sch). The aim of this paper is to report gender differences in the prevalence, associated factors and severity-related factors of MetS in first-treatment and drug-naïve (FTDN) patients with Sch.

METHODS

A total of 668 patients with FTDN Sch were included in this study. We collected socio-demographic and general clinical information on the target population, measured and evaluated common metabolic parameters and routine biochemical indicators, and assessed the severity of psychiatric symptoms using Positive and Negative Symptom Scale (PANSS).

RESULTS

In the target group, the prevalence of MetS was significantly higher in women (13.44%, 57/424) than in men (6.56%, 16/244). In the males, waist circumference (WC), fasting blood glucose (FBG), diastolic blood pressure (DBP), and triglycerides (TG) were risk factors for MetS, while systolic blood pressure (SBP), TG, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and platelet (PLT) were risk factors for the females. More importantly, for the females, we found that age, LDL-C, PANSS scores and blood creatinine (CRE) were risk factors for higher MetS scores, while onset age and hemoglobin (HGB) were protective factors.

CONCLUSION

There are significant gender differences in the prevalence of MetS and its factors among patients with FTDN Sch. The prevalence of MetS is higher and the factors that influence MetS are more numerous and extensive in females. The mechanisms of this difference need further research and clinical intervention strategies should be formulated with gender differences.

Subjective cognitive functioning, depressive symptoms, and objective cognitive functioning in people with treatment-resistant psychosis

Introduction: Relationships between subjective cognitive functioning (SCF), objective cognitive functioning (OCF), and depressive symptoms are poorly understood in treatment-resistant psychosis (TRP). This study (a) compares SCF in TRP using positively and negatively worded scales, (b) assess these scales' accuracy, and (c) explores the association between these scales and depressive symptoms. We hypothesised that both SCF scales would be highly correlated, minimally associated with OCF, and similarly associated with depressive symptoms. Methods: Archival clinical data from 52 TRP inpatients was utilised. OCF composite scores were derived from a broad neuropsychological battery. SCF was assessed using the norm-referenced PROMIS 2.0 Cognitive Abilities (positively worded) and Concerns (negatively worded) subscales. A depressive symptom score was derived from the Positive and Negative Syndrome Scale. Results: SCF ratings were higher in patients than OCF. There was a small but significant correlation between PROMIS subscales (r = .30). Neither PROMIS subscale was associated with OCF (r = -.11, r = .01). Depressive symptoms were correlated with the positively (r = -.29) but not negatively worded scale (r = -.13). Conclusion: Individuals with TRP inaccurately rate their cognitive functioning and tend to overestimate their ability. Positively and negatively worded SCF scales associate variably with depressive symptoms, indicating they may not be used interchangeably in TRP.

Large-scale evaluation of the Positive and Negative Syndrome Scale (PANSS) symptom architecture in schizophrenia

Although the Positive and Negative Syndrome Scale (PANSS) is widely utilized in schizophrenia research, variability in specific item loading exist, hindering reproducibility and generalizability of findings across schizophrenia samples. We aim to establish a common PANSS factor structure from a large multi-ethnic sample and validate it against a meta-analysis of existing PANSS models. Schizophrenia participants (N = 3511) included in the current study were part of the Singapore Translational and Clinical Research Program (STCRP) and the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE). Exploratory Factor Analysis (EFA) was conducted to identify the factor structure of PANSS and validated with a meta-analysis (N = 16,171) of existing PANSS models. Temporal stability of the PANSS model and generalizability to individuals at ultra-high risk (UHR) of psychosis were evaluated. A five-factor solution best fit the PANSS data. These were the i) Positive, ii) Negative, iii) Cognitive/disorganization, iv) Depression/anxiety and v) Hostility factors. Convergence of PANSS symptom architecture between EFA model and meta-analysis was observed. Modest longitudinal reliability was observed. The schizophrenia derived PANSS factor model fit the UHR population, but not vice versa. We found that two other domains, Social Amotivation (SA) and Diminished Expression (DE), were nested within the negative symptoms factor. Here, we report one of the largest transethnic factorial structures of PANSS symptom domains (N = 19,682). Evidence reported here serves as crucial consolidation of a common PANSS structure that could aid in furthering our understanding of schizophrenia.

EEG Source Network for the Diagnosis of Schizophrenia and the Identification of Subtypes Based on Symptom Severity-A Machine Learning Approach

A precise diagnosis and a comprehensive assessment of symptom severity are important clinical issues in patients with schizophrenia (SZ). We investigated whether electroencephalography (EEG) features obtained from EEG source network analyses could be effectively applied to classify the SZ subtypes based on symptom severity. Sixty-four electrode EEG signals were recorded from 119 patients with SZ (53 males and 66 females) and 119 normal controls (NC, 51 males and 68 females) during resting-state with closed eyes. Brain network features (global and local clustering coefficient and global path length) were calculated from EEG source activities. According to positive, negative, and cognitive/disorganization symptoms, the SZ patients were divided into two groups (high and low) by positive and negative syndrome scale (PANSS). To select features for classification, we used the sequential forward selection (SFS) method. The classification accuracy was evaluated using 10 by 10-fold cross-validation with the linear discriminant analysis (LDA) classifier. The best classification accuracy was 80.66% for estimating SZ patients from the NC group. The best classification accuracy between low and high groups in positive, negative, and cognitive/disorganization symptoms were 88.10%, 75.25%, and 77.78%, respectively. The selected features well-represented the pathological brain regions of SZ. Our study suggested that resting-state EEG network features could successfully classify between SZ patients and the NC, and between low and high SZ groups in positive, negative, and cognitive/disorganization symptoms.

Negative symptom configuration in first episode Schizophrenia: findings from the "Parma Early Psychosis" program

Purpose: Identifying distinct dimensions of negative symptoms in First Episode Schizophrenia (FES) might result in a better understanding and treatment of this invalidating symptomatology. Aim of this study was to examine negative symptom structure in FES patients using the Positive and Negative Syndrome Scale (PANSS).Materials and Methods: All 147 participants, aged 12-35 years, completed the PANSS and the Global Assessment of Functioning (GAF) scale. A principal component analysis with varimax rotation was performed to investigate PANSS negative symptom structure in the FES total sample.Results: A 2-factor model (i.e. "Expressive Deficits" and "Asociality" dimensions) was identified. Only "Expressive Deficits" domain had a significant negative correlation with baseline GAF score.Conclusions: This bipartite solution seems to be adequate to describe the phenomenological variety of negative symptoms experienced by FES individuals at the point of entry in early intervention services.

Efficacy of lurasidone across five symptom dimensions of schizophrenia: Pooled analysis of short-term, placebo-controlled studies

Objective:

To evaluate the efficacy of lurasidone for schizophrenia using an established five-factor model of the Positive and Negative Syndrome Scale (PANSS).

Methods:

Patient-level data were pooled from five randomized, double-blind, placebo-controlled, 6-week studies of lurasidone (fixed doses, 40–160 mg/d) for patients with an acute exacerbation of schizophrenia. Changes in five established PANSS factors were assessed using mixed-model repeated measures analysis.

Results:

Compared with placebo (n = 496), lurasidone (n = 1029, dose groups pooled) significantly improved the PANSS total score at Week 6 (−22.6 vs. −12.8; P < 0.001; effect size, 0.45), as well as all factor scores (P < 0.001 for each): positive symptoms (−8.4 vs. −6.0; effect size, 0.43), negative symptoms (−5.2 vs. −3.3; effect size, 0.33), disorganized thought (−4.9 vs. −2.8; effect size, 0.42), hostility/excitement (−2.7 vs. −1.6; effect size, 0.31), and depression/anxiety (−3.2 vs. −2.3; effect size, 0.31). Separation from placebo occurred at Week 1 for the positive symptoms, disorganized thought, and hostility/excitement factors and at Week 2 for the other factors.

Conclusions:

In this pooled analysis of short-term studies in patients with acute schizophrenia, lurasidone demonstrated significant improvement for each of the five PANSS factor scores, indicating effectiveness across the spectrum of schizophrenia symptoms.

Neurobiological Divergence of the Positive and Negative Schizophrenia Subtypes Identified on a New Factor Structure of Psychopathology Using Non-negative Factorization: An International Machine Learning Study

BACKGROUND

Disentangling psychopathological heterogeneity in schizophrenia is challenging, and previous results remain inconclusive. We employed advanced machine learning to identify a stable and generalizable factorization of the Positive and Negative Syndrome Scale and used it to identify psychopathological subtypes as well as their neurobiological differentiations.

METHODS

Positive and Negative Syndrome Scale data from the Pharmacotherapy Monitoring and Outcome Survey cohort (1545 patients; 586 followed up after 1.35 ± 0.70 years) were used for learning the factor structure by an orthonormal projective non-negative factorization. An international sample, pooled from 9 medical centers across Europe, the United States, and Asia (490 patients), was used for validation. Patients were clustered into psychopathological subtypes based on the identified factor structure, and the neurobiological divergence between the subtypes was assessed by classification analysis on functional magnetic resonance imaging connectivity patterns.

RESULTS

A 4-factor structure representing negative, positive, affective, and cognitive symptoms was identified as the most stable and generalizable representation of psychopathology. It showed higher internal consistency than the original Positive and Negative Syndrome Scale subscales and previously proposed factor models. Based on this representation, the positive-negative dichotomy was confirmed as the (only) robust psychopathological subtypes, and these subtypes were longitudinally stable in about 80% of the repeatedly assessed patients. Finally, the individual subtype could be predicted with good accuracy from functional connectivity profiles of the ventromedial frontal cortex, temporoparietal junction, and precuneus.

CONCLUSIONS

Machine learning applied to multisite data with cross-validation yielded a factorization generalizable across populations and medical systems. Together with subtyping and the demonstrated ability to predict subtype membership from neuroimaging data, this work further disentangles the heterogeneity in schizophrenia.

[Effect of Lurasidone on symptoms of schizophrenia in five-factor dimensional model: pooled analysis of two short-term, randomized, double-blind, placebo-controlled studies in patients from Russia and Ukraine]

AIM

Evaluation of a new five-factor dimensional model of schizophrenia in recent revisions of classifications of mental disorders (DSM-5 and ICD-11) dictates the need to use this approach in conducting a comprehensive assessment of the effectiveness of new antipsychotic agents, including ethnically homogeneous populations of patients.

MATERIAL AND METHODS

Post-hoc analysis of pooled data from two randomized, double-blind, placebo-controlled, 6-week clinical studies (RCTs) of lurasidone (fixed doses, 40, 80, 120 or 160 mg/d) in patients experiencing an acute exacerbation of schizophrenia. Changes in PANSS total score, CGI-S score and five established PANSS factors were assessed using mixed-model repeated measures analysis.

RESULTS

Lurasidone (n=162, dose groups pooled) compared with placebo (n=68), significantly improved the PANSS total score at Week 6 (-23.0 vs. -10.5; p<0.001; effect size 0.82) as well as all PANSS factor scores: positive symptoms (-8.5 vs. -4.2; p<0.001; effect size 0.88), negative symptoms (-4.4 vs. -2.8; p=0.011, effect size 0.44), disorganized thoughts (-4.4 vs. -2.1; p<0.001; effect size 0.70), hostility/excitement (-2.7 vs. -0.7; p<0.001; effect size 0.66), and depression/anxiety (-3.5 vs. -2.2; p=0.002; effect size 0.53).

CONCLUSION

Lurasidone demonstrated significant improvement for both PANSS total score and each of the five PANSS factor scores, indicating effectiveness across the broad spectrum of schizophrenia symptoms. Effect size for both PANSS total score and each of the five PANSS factor scores for the local population was higher than for the wider population, which included patients from various countries.

Association of DTNBP1 With Schizophrenia: Findings From Two Independent Samples of Han Chinese Population

OBJECTIVES

Schizophrenia (SZ) is a complex psychiatric disorder that has a strong genetic basis. Dystrobrevin-binding protein 1 (DTNBP1) is one of the genes thought to be pivotal in regulating the glutamatergic system. Studies have suggested that variations in DTNBP1 confer susceptibility to SZ and clinical symptoms. Here, we performed a two-stage independent verification study to identify polymorphisms of the DTNBP1 gene that might be associated with SZ in the Han Chinese population.

METHODS

In stage 1, 14 single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 healthy controls (HCs) using the Illumina GoldenGate assays on a BeadStation 500G Genotyping System. In stage 2, ten SNPs were genotyped in an independent sample of 1,031 SZ patients and 621 HCs using the Illumina 660k Genotyping System. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale.

RESULTS

There was a significant association related to allele frequency, and a trend association in relation to genotype between SZ patients and HCs at rs4712253 (p = 0.03 and 0.05, respectively). These associations were not evident following Bonferroni correction (p > 0.05 for both). Haplotype association analysis revealed that only two haplotypes (GAG and GAA; rs16876575-rs9464793-rs4712253) were significantly different between SZ patients and HCs (χ² = 4.24, 6.37, p = 0.04 and 0.01, respectively). In addition, in SZ patients there was a significant association in the rs4964793 genotype for positive symptoms, and in the rs1011313 genotype for excitement/hostility symptoms (p = 0.01 and 0.002, respectively). We found a significant association in the baseline symbol digital modalities test (SDMT), forward-digital span (DS), backward-DS, and semantic fluency between SZ patients and HCs (p < 0.05 for all). Finally, the SNP rs1011313 genotypes were associated with SDMT in SZ patients (p = 0.04).

CONCLUSION

This study provides further evidence that SNP rs4712253 of DTNBP1 has a nominal association with SZ in the Han Chinese population. Such a genotype variation may play a role in psychopathology and cognitive function.

Meta-analysis of the positive and Negative Syndrome Scale (PANSS) factor structure

A meta-analysis of the results of 45 factor analyses (n = 22,812) of the Positive and Negative Syndrome Scale (PANSS) was conducted. Meta-analyses of the PANSS was conducted using both a co-occurrence similarity matrix and reproduced correlations. Both methods produced similar results. Five factors (Positive Symptoms, Negative Symptoms, Disorganization, Affect and Resistance) emerged clearly across both analyses. The factors and the items defining them were Positive Symptoms (P1 Delusions, G9 Unusual thought content, P3 Hallucinatory behavior, P6 Suspiciousness and persecution, P5 Grandiosity), Negative Symptoms (N2 Emotional withdrawal, N1 Blunted affect, N4 Passive apathetic social withdrawal, N6 Lack of spontaneity, N3 Poor rapport, G7 Motor retardation, G16 Active social avoidance), Disorganization often termed Cognitive (P2 Conceptual disorganization, G11 Poor attention, N5 Difficulty in abstract thinking, G13 Disturbance of volition, N7 Stereotyped thinking, G5 Mannerisms/posturing, G15 Preoccupation, G10 Disorientation), Affect often termed Depression-Anxiety (G2 Anxiety, G6 Depression, G3 Guilt feelings, G4 Tension, G1 Somatic concern) and a small fifth factor that might be characterized as Resistance or Excitement/Activity (P7 Hostility, G14 Poor impulse control, P4 Excitement, G8 Uncooperativeness). Items G1, G4, G10, P5, G5, G15 may not be core items for the PANSS factors and G12 lack of judgment is not a core item. Results of the PANSS meta-analyses were relatively similar to those for meta-analysis of both the BPRS and BPRS-E all of which contain the original 18 BPRS items. The PANSS is distinguished by a much larger number of items to clearly define and measure Negative Symptoms as well as a sufficient number of items to much more clearly identify a Disorganization factor than the BPRS or BPRS-E.

Distinct Differences in Emotional Recognition According to Severity of Psychotic Symptoms in Early-Stage Schizophrenia

Patients with schizophrenia are characterized by deficits in their ability to identify facial expressions of emotion, which are associated with impaired social and occupational function. An understanding of the deficits of facial affect recognition (FAR) early in the course of the illness can improve early intervention efforts to ameliorate potential functional deterioration. This study aimed to investigate the characteristics and correlations between psychotic symptoms and FAR deficits in patients with early-stage schizophrenia using data from the Korean Early Psychosis Cohort Study. Patients with schizophrenia were divided into three groups: 1) severely and markedly ill (n = 112), 2) moderately ill (n = 96), and 3) mildly ill (n = 115). These groups were compared with age- and sex-matched healthy controls. The FAR test was developed using Korean emotional faces from the Korean Facial Expressions of Emotion database. Error rates, correct response times, and nonresponse rates of each subset were calculated. Several psychopathology assessments were also performed. There were significantly more deficits associated with the recognition of anger (p < 0.01), fear (p < 0.01), and contempt (p < 0.01) in the three patient groups than in the healthy control group. In the severely and markedly ill states, all emotions apart from surprise had impaired error rates (p < 0.01 for all analyses). The error rates for happiness, sadness, disgust, surprise, and neutral faces were not significantly different between mildly ill patients and healthy controls. All emotions, except for sadness, had significantly more delayed correct response times in all patient groups than in the healthy controls (p < 0.01 for all analyses). The severity of psychotic symptoms was positively correlated with the happiness and neutral error rates, and depression was positively correlated with the happiness error rates. General social function was negatively correlated with the error rates for happiness, sadness, fear, disgust, and surprise. Overall, our results show that the severity of psychosis and clinical symptoms leads to distinct differences in certain emotions of patients with early-stage schizophrenia. It is considered that these specific emotional characteristics will help deepen our understanding of schizophrenia and contribute to early intervention and recovery of social function in patients with schizophrenia.

Common and Specific Functional Activity Features in Schizophrenia, Major Depressive Disorder, and Bipolar Disorder

Objectives: Schizophrenia (SZ), major depressive disorder (MDD), and bipolar disorder (BD) are serious mental disorders with distinct diagnostic criteria. They share common clinical and biological features. However, there are still only few studies on the common and specific brain imaging changes associated with the three mental disorders. Therefore, the aim of this study was to identify the common and specific functional activity and connectivity changes in SZ, MDD, and BD. Methods: A total of 271 individuals underwent functional magnetic resonance imaging: SZ (n = 64), MDD (n = 73), BD (n = 41), and healthy controls (n = 93). The symptoms of SZ patients were evaluated by the Positive and Negative Syndrome Scale. The Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) were used to evaluate the symptoms of MDD patients. The BDI, BAI, and Young Mania Rating Scale were used to evaluate the symptoms of MDD and BD patients. In addition, we compared the fALFF and functional connectivity between the three mental disorders and healthy controls using two sample t-tests. Results: Significantly decreased functional activity was found in the right superior frontal gyrus, middle cingulate gyrus, left middle frontal gyrus, and decreased functional connectivity (FC) of the insula was found in SZ, MDD, and BD. Specific fALFF changes, mainly in the ventral lateral pre-frontal cortex, striatum, and thalamus were found for SZ, in the left motor cortex and parietal lobe for MDD, and the dorsal lateral pre-frontal cortex, orbitofrontal cortex, and posterior cingulate cortex in BD. Conclusion: Our findings of common abnormalities in SZ, MDD, and BD provide evidence that salience network abnormality may play a critical role in the pathogenesis of these three mental disorders. Meanwhile, our findings also indicate that specific alterations in SZ, MDD, and BD provide neuroimaging evidence for the differential diagnosis of the three mental disorders.

A reassessment of the higher-order factor structure of the German Schizotypal Personality Questionnaire (SPQ-G) in German-speaking adults

The Schizotypal Personality Questionnaire (SPQ) is a widely-used self-report instrument for the assessment of schizotypal personality traits. However, the factor structure of scores on English and non-English translations of the SPQ has been a matter of debate. With little previous factorial evaluation of the German version of the SPQ (SPQ-G), we re-assessed the higher-order factor structure of the measure. A total of 2,428 German-speaking adults from Central Europe (CE) and the United Kingdom (UK) completed the SPQ-G. Confirmatory factor analysis - testing proposed 2-, 3-, and 4-factor models of SPQ-G scores - indicated that the 4-factor solution had best fit. Partial measurement invariance across cultural group (CE and UK) and sex was obtained for the 4-factor model. Further analyses showed CE participants had significantly higher scores than UK participants on one schizotypal facet. These results suggest that scores on the SPQ-G are best explained in terms of a higher-order, 4-factor solution in German migrant and non-migrant adults.

The relationship between excitement symptom severity and extrastriatal dopamine D2/3 receptor availability in patients with schizophrenia: a high-resolution PET study with [18F]fallypride

The purpose of this study was to investigate the relationship between specific symptom severity and D_2/3 receptor availability in extrastriatal regions in outpatients with schizophrenia to shed light on the role of extrastriatal dopaminergic neurotransmission in the pathophysiology of symptoms of schizophrenia. Sixteen schizophrenia patients receiving relatively low-dose maintenance atypical antipsychotics and seventeen healthy controls underwent 3-Tesla magnetic resonance imaging and high-resolution positron emission tomography with [¹⁸F]fallypride. For D_2/3 receptor availability, the binding potential with respect to non-displaceable compartment (BP_ND) was derived using the simplified reference tissue model. The BP_ND values were lower in patients on antipsychotic treatment than in controls across all regions with large effect sizes (1.03-1.42). The regions with the largest effect size were the substantia nigra, amygdala, and insula. Symptoms of schizophrenia were assessed using a five-factor model of the Positive and Negative Syndrome Scale (PANSS). The region of interest-based analysis showed that PANSS excitement factor score had a significant positive correlation with the [¹⁸F]fallypride BP_ND in the insula. The equivalent dose of antipsychotics was not significantly correlated with PANSS factor scores or regional BP_ND values. The voxel-based analysis also revealed a significant positive association between the PANSS excitement factor and the [¹⁸F]fallypride BP_ND in the insula. The present study revealed a significant association between excitement symptom severity and D_2/3 receptor availability in the insula in schizophrenia, suggesting a possible important role of D_2/3 receptor-mediated neurotransmission in the insula and related limbic system in the pathophysiology of this specific symptom cluster.

Association between cerebral dopamine neurotrophic factor (CDNF) 2 polymorphisms and schizophrenia susceptibility and symptoms in the Han Chinese population

Background

Schizophrenia (SZ) is a complex polygenic psychiatric disorder caused in part by abnormal dopamine levels. Cerebral dopamine neurotrophic factor (CDNF) 2 is known to protect and repair the dopaminergic system. Dopamine dysfunction is one of the pathogenesis of SZ. However, the relationship between CDNF2 and SZ has not been previously investigated. We speculated that CDNF2 may be a susceptibility factor for SZ.

Methods

To address this issue, we carried out a study to investigate the association between CDNF2 and SZ in the total sample 1371 (670 SZ patients and 701 healthy controls) Han Chinese population. Stage 1 included 528 SZ patients and 528 healthy controls; and stage 2 included 142 SZ patients and 173 healthy controls. The allele and genotype frequencies of five single nucleotide polymorphisms (rs2577074, rs2577075, rs2249810, rs6506891, and rs2118343) of CDNF2 were compared between patients and controls.

Results

We found a significant association in allele and genotype frequencies between the two groups at rs2249810 (χ² = 4.38 and 6.45, respectively; P = 0.03 and 0.04, respectively). An association was also observed in males at rs2249810 (χ² = 8.76; P = 0.03). Haplotype TGATC differed between SZ and controls in stage 2 samples (χ² = 6.38; P = 0.01), and rs2118343 genotypes were associated with negative factor scores (F = 4.396; P = 0.01).

Conclusions

These results suggest that rs2249810 and haplotype TGATC of CDNF2 are an SZ susceptibility locus and factor, respectively, and that rs2118343 genotypes are associated with negative symptoms of SZ in the Han Chinese population.

Depressive, anxiety and hypomanic symptoms in schizophrenia may be driven by tryptophan catabolite (TRYCAT) patterning of IgA and IgM responses directed to TRYCATs

The aim of this study was to delineate the associations between the tryptophan catabolite (TRYCAT) pathway and affective symptoms in schizophrenia. Towards this end we measured immunoglobulin (Ig)A and IgM responses to relatively noxious TRYCATs, namely quinolinic (QA), xanthurenic (XA), picolinic (PA) acid and 3-OH-kynurenine (3HK), and generally protective TRYCATs, namely anthranilic (AA) and kynurenic (KA) acid in 80 patients with schizophrenia and 40 healthy controls. The Hamilton Rating Scale for Depression (HDRS) and anxiety (HAMA), Young Mania Rating Scale (YMRS) as well as the Positive and Negative Symptoms Scale of Schizophrenia (PANSS) were measured. Depression, anxiety and hypomanic as well as negative and positive symptoms were associated with increased IgA responses to PA. Increased IgA responses to XA were associated with anxiety, hypomanic and negative symptoms. Moreover, depressive, anxiety, hypomanic and negative symptoms were characterized by increased IgA responses to the noxious (XA+3HK+QA+PA)/protective (AA+KA) TRYCAT ratio. All symptom dimensions were associated with increased IgM responses to QA, while depressive, anxiety, positive and negative symptoms were accompanied by lowered IgM responses to 3HK. Hypomanic symptoms were additionally accompanied by lowered IgM responses to AA, and negative symptoms by increased IgM responses to KA. In conclusion, both shared and distinct alterations in the activity of the TRYCAT pathway, as well as its regulatory factors and consequences, may underpin affective and classical psychotic symptoms of schizophrenia. Increased mucosa-generated production of noxious TRYCATs, especially PA, and specific changes in IgM-mediated regulatory activities may be associated with the different symptom dimensions of schizophrenia.

Physio-somatic symptoms in schizophrenia: association with depression, anxiety, neurocognitive deficits and the tryptophan catabolite pathway

To investigate the frequency of physio-somatic symptoms (PS) symptoms in schizophrenia and their relation to positive, negative and affective symptoms; neurocognitive deficits and impairments in the tryptophan catabolite (TRYCAT) pathway. Eighty four patients with schizophrenia and 40 healthy controls were assessed using the 12 item Fibromyalgia and Chronic Fatigue Syndrome Rating scale (FF) and scales for negative and positive symptoms, depression and anxiety. Cognitive functioning was tested using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Other assessments included: immunoglobulin (Ig)A and IgM responses to tryptophan catabolites (TRYCATs), namely quinolinic (QA), 3-OH-kynurenine (3HK), picolinic (PA), xanthurenic (XA) and kynurenic acid (KA) and anthranilic acid (AA). More than 50% of the patients studied had elevated levels of physio-somatic (PS) symptoms, significantly co-occurring with depression and anxiety, but not with negative or positive symptoms. PS symptoms were significantly associated with IgA/IgM responses to TRYCATs, including increased IgA responses to 3 HK, PA and XA, and lowered IgA to QA and AA. Fatigue, muscle pain and tension, autonomic and cognitive symptoms and a flu-like malaise were strongly associated with cognitive impairments in spatial planning and working memory, paired associative learning, visual sustained attention and attention set shifting. PS symptoms in schizophrenia aggregate with depression and anxiety symptoms and may be driven by TRYCAT patterning of IgA/IgM-responses, with IgA indicating mucosal-mediated changes and IgM indicating regulatory functions. As such, the patterning of IgA/IgM responses to TRYCATs may indicate differential TRYCATs regulation of neuronal and glia activity that act to regulate PS signalling in schizophrenia.

Dimensions of schizophrenia and their time course of response to a second generation antipsychotic olanzapine-A clinical study

BACKGROUND

The pattern of symptom response to second generation antipsychotics (SGAs) has not been studied extensively. Understanding the time course of symptom response would help to rationally monitor patient progress.

OBJECTIVE

To determine the short-term differential time course of response of symptom dimensions of first episode schizophrenia viz., negative, positive symptoms and 5 factors of anergia, thought disturbance, activation, paranoid-belligerence and depression to treatment with SGA olanzapine.

METHODS

57 drug naive patients with schizophrenia were treated for 4 weeks with olanzapine 10mg/day, increased to 20mg/day in 1 week. Weight was recorded and ratings with the Positive and Negative Syndrome scale (PANSS), the Simpson Angus Scale (SAS) were performed weekly.

RESULTS

43 patients completed 4 weeks of assessment. Scores on all of the dimensions improved. By the end of week 1, only positive syndrome, thought disturbance and paranoid-belligerence dimensions improved. Maximum improvement was seen with paranoid-belligerence by week 1, followed by positive syndrome in week 2, and depression at week 3. The percentage improvement in positive syndrome was significantly greater than negative. Over 4 weeks there was a mean weight gain of 2kg and there were significant extrapyramidal symptoms.

CONCLUSIONS

Olanzapine produced reduction in all dimensions, but the pace of responding of individual dimensions differed. Longer-term studies comparing SGAs with first generation antipsychotics are needed.

Dimensional approaches to schizophrenia: A comparison of the Bern Psychopathology scale and the five-factor model of the Positive and Negative Syndrome Scale

The aim was to examine to what extent the dimensions of the BPS map the five factors derived from the PANSS in order to explore the level of agreement of these alternative dimensional approaches in patients with schizophrenia. 149 inpatients with schizophrenia spectrum disorders were recruited. Psychopathological symptoms were assessed with the Bern Psychopathology Scale (BPS) and the Positive and Negative Syndrome Scale (PANSS). Linear regression analyses were conducted to explore the association between the factors and the items of the BPS. The robustness of patterns was evaluated. An understandable overlap of both approaches was found for positive and negative symptoms and excitement. The PANSS positive factor was associated with symptoms of the affect domain in terms of both inhibition and disinhibition, the PANSS negative factor with symptoms of all three domains of the BPS as an inhibition and the PANSS excitement factor with an inhibition of the affect domain and a disinhibition of the language and motor domains. The results show that here is only a partial overlap between the system-specific approach of the BPS and the five-factor PANSS model. A longitudinal assessment of psychopathological symptoms would therefore be of interest.

Self-perceived cognitive deficits and their relationship with internalized stigma and quality of life in patients with schizophrenia

BACKGROUND

We investigated self-perceived cognitive deficits and their relationship with internalized stigma and quality of life in patients with schizophrenia in order to shed light on the clinical correlates of subjective cognitive deficits in schizophrenia.

METHODS

Seventy outpatients with schizophrenia were evaluated. Patients' self-perceived cognitive deficits, internalized stigma, and subjective quality of life were assessed using the Scale to Investigate Cognition in Schizophrenia (SSTICS), the Internalized Stigma of Mental Illness Scale (ISMI), and the Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4), respectively. Correlation and regression analyses controlling for the severity of symptoms of schizophrenia were performed, and a mediation analysis was conducted to examine the hypothesis that internalized stigma mediates the relationship between self-perceived cognitive deficits and subjective quality of life.

RESULTS

Pearson's partial correlation analysis showed significant correlations among the SSTICS, ISMI, and SQLS-R4 scores (P<0.01). Multiple regression analysis showed that the SSTICS and ISMI scores significantly predicted the SQLS-R4 score (P<0.01). Mediation analysis revealed that the strength of the association between the SSTICS and SQLS-R4 scores decreased from β=0.74 (P<0.01) to β=0.56 (P<0.01), when the ISMI score was statistically controlled. The Sobel test revealed that this difference was significant (P<0.01), indicating that internalized stigma partially mediated the relationship between self-perceived cognitive deficits and quality of life.

CONCLUSION

The present study indicates that self-perceived cognitive deficits are significantly associated with internalized stigma and quality of life. Furthermore, internalized stigma was identified as a partial mediator of the relationship between self-perceived cognitive deficits and quality of life. These findings suggest that clinicians should be aware that patients with schizophrenia experience significantly greater self-stigma when they suffer subjective cognitive deficits, and that this may further compromise their quality of life.

Associations between five-factor model of the Positive and Negative Syndrome Scale and plasma levels of monoamine metabolite in patients with schizophrenia

The five-factor model of the Positive and Negative Syndrome Scale (PANSS) for schizophrenia symptoms is the most common multiple-factor model used in analyses; its use may improve evaluation of symptoms in schizophrenia patients. Plasma monoamine metabolite levels are possible indicators of clinical symptoms or response to antipsychotics in schizophrenia. We investigated the association between five-factor model components and plasma monoamine metabolites levels to explore the model's biological basis. Plasma levels of homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylglycol (MHPG), and 5-hydroxyindoleacetic acid (5-HIAA) were measured using high-performance liquid chromatography in 65 Japanese patients with schizophrenia. Significant negative correlation between plasma 5-HIAA levels and the depression/anxiety component was found. Furthermore, significant positive correlation was found between plasma MHPG levels and the excitement component. Plasma HVA levels were not correlated with any five-factor model component. These results suggest that the five-factor model of the PANSS may have a biological basis, and may be useful for elucidating the psychopathology of schizophrenia. Assessment using the five-factor model may enable understanding of monoaminergic dysfunction, possibly allowing more appropriate medication selection. Further studies of a larger number of first-episode schizophrenia patients are needed to confirm and extend these results.

Validation of a five-factor model of a Chinese Mandarin version of the Positive and Negative Syndrome Scale (CMV-PANSS) in a sample of 813 schizophrenia patients

OBJECTIVES

The Positive and Negative Syndrome Scale (PANSS) is one of the most widely used instruments for measuring the severity of schizophrenia. However, until now, there has not been a published, validated Chinese Mandarin version of the five-factor model PANSS with confirmatory factor analysis (CFA) for schizophrenic patients in Taiwan.

METHODS

A total of 813 subjects were recruited. Internal consistency was evaluated with Cronbach's alpha coefficient. For test re-test reliability, 57 patients were reassessed and intra-class correlation coefficients were calculated. For validity, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) using a Structured Equation Model were implemented to identify the factor model.

RESULTS

The Cronbach's alpha coefficient was 0.928. The intra-class coefficient was 0.878 (95% CI: 0.79-0.92). The final model was composed of five factors. EFA explained a total of 64.2% of the variance. CFA indicated a good fitting model. Except for the PANSS items G7 (motor retardation), G8 (uncooperativeness), N5 (abstract thinking), and G10 (disorientation), this study found that the items loaded on these factors were similar to the consensus items published in prior studies.

CONCLUSIONS

In summary, these findings support the Chinese Mandarin version of the PANSS as a reliable and valid instrument for the assessment of the severity of psychopathology in hospitalized, stable patients with schizophrenia. More effective and specific treatment models targeting sub-culture differences are expected to be developed in future studies.

Schizophrenia symptoms and brain network efficiency: A resting-state fMRI study

Schizophrenia is a condition marked by a disrupted brain functional network. In schizophrenia, the brain network is characterized by reduced distributed information processing efficiency; however, the correlation between information processing efficiency and the symptomatology of schizophrenia remains unclear. Few studies have examined path length efficiencies in schizophrenia. In this study, we examined small-world network metrics computed from resting state functional magnetic resonance imaging data collected from 49 patients with schizophrenia and 28 healthy people. We calculated brain network efficiency using graph theoretical analysis of the networks of brain areas, as defined by the Automated Anatomical Labeling parcellation scheme, and investigated efficiency correlations by using the 5-factor model of psychopathology, which considers the various domains of schizophrenic symptoms and might also consider discrete pathogenetic processes. The global efficiency of the resting schizophrenic brains was lower than that of the healthy controls, but local efficiency did not differ between the groups. The severity of psychopathology, negative symptoms, and depression and anxiety symptoms were correlated with global efficiency in schizophrenic brains. The severity of psychopathology was correlated with increased network efficiency from short-range connections, but not networks from long-range connections. Our findings indicate that schizophrenic psychopathology is correlated with brain network information processing efficiency.

Longitudinal relations between symptoms, neurocognition, and self-concept in schizophrenia

Objective: Cognitive models suggest that the self-concept of persons with psychosis can be fundamentally affected. Self-concepts were found to be related to different symptom domains when measured concurrently. Longitudinal investigations to disentangle the possible causal associations are rare.

Method: We examined a sample of 160 people with a diagnosis of schizophrenia who took part in a psychotherapy study. All participants had the DSM-IV diagnosis of a schizophrenia and pronounced negative symptoms. Neurocognition, symptoms, and self-concepts were assessed at two time points 12 months apart. Structural equation modeling was used to test whether symptoms influence self-concepts (scar-model) or self-concepts affect symptoms (vulnerability model).

Results: Negative symptoms correlated concurrently with self-concepts. Neurocognitive deficits are associated with more negative self-concepts 12 months later. Interpersonal self-concepts were found to be relevant for paranoia.

Conclusion: The findings implicate that if deficits in neurocognition are present, fostering a positive self-concept should be an issue in therapy. Negative interpersonal self-concept indicates an increased risk for paranoid delusions in the course of 1 year. New aspects for cognitive models in schizophrenia and clinical implications are discussed.

Association Study of N-Methyl-D-Aspartate Receptor Subunit 2B (GRIN2B) Polymorphisms and Schizophrenia Symptoms in the Han Chinese Population

Schizophrenia (SZ) is a common and complex psychiatric disorder that has a significant genetic component. The glutamatergic system is the major excitatory neurotransmitter system in the central nervous system, and is mediated by N-methyl-D-aspartate (NMDA) receptors. Disturbances in this system have been hypothesized to play a major role in SZ pathogenesis. Several studies have revealed that the NMDA receptor subunit 2B (GRIN2B) potentially associates with SZ and its psychiatric symptoms. In this study, we performed a case–control study to identify polymorphisms of the GRIN2B gene that may confer susceptibility to SZ in the Han Chinese population. Thirty-four single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 control subjects. A significant association was observed in allele and genotype between SZ and controls at rs2098469 (χ² = 8.425 and 4.994; p = 0.025 and 0.014, respectively). Significant associations were found in the allele at rs12319804 (χ² = 4.436; p = 0.035), as well as in the genotype at rs12820037 and rs7298664 between SZ and controls (χ² = 11.162 and 38.204; p = 0.003 and 4.27×10^-8, respectively). After applying the Bonferroni correction, rs7298664 still had significant genotype associations with SZ (p = 1.71×10^-7). In addition, rs2098469 genotype and allele frequencies, and 12820037 allele frequencies were nominally associated with SZ. Three haplotypes, CGA (rs10845849—rs12319804—rs10845851), CC (rs12582848—rs7952915), and AAGAC (rs2041986—rs11055665—rs7314376—rs7297101—rs2098469), had significant differences between SZ and controls (χ² = 4.324, 4.582, and 4.492; p = 0.037, 0.032, and 0.034, respectively). In addition, three SNPs, rs2098469, rs12820037, and rs7298664, were significantly associated with cognition factors PANSS subscores in SZ (F = 16.799, 7.112, and 13.357; p = 0.000, 0.017, and 0.000, respectively). In conclusion, our study provides novel evidence for an association between GRIN2B polymorphisms and SZ susceptibility and symptoms in the Han Chinese population.

Serotonin transporter availability in thalamic subregions in schizophrenia: a study using 7.0-T MRI with [(11)C]DASB high-resolution PET

The serotonin transporter (SERT) is an integral protein that provides an index of serotonergic innervation. Until recently, few studies have investigated SERT binding in thalamic subregions in schizophrenia. The purpose of this study was to examine SERT availability in thalamic subdivisions (anterior nucleus, mediodorsal nucleus, and pulvinar) using 7.0-T magnetic resonance imaging (MRI) and high-resolution positron emission tomography (PET) with (11)C-3-amino-4-(2-dimethylaminomethylphenylthio)benzonitrile ([(11)C]DASB) in schizophrenia. Antipsychotic-free patients with schizophrenia (n=12) and healthy controls (n=15) underwent PET and MRI scans. For SERT availability, the binding potential with respect to non-displaceable compartment (BPND) was derived using the simplified reference tissue model (SRTM2). The analysis revealed that there were no significant differences in SERT availability between the two groups. In patients with schizophrenia, the severity of negative symptoms had a negative correlation with SERT availability in the anterior nucleus of the left thalamus. The present study did not reveal significant differences in SERT availability in thalamic subdivisions between patients with schizophrenia and control subjects. The association of SERT availability in the anterior nucleus with negative symptoms may suggest a role for the anterior thalamic nucleus in the pathophysiology of symptoms of schizophrenia. The ultra-high resolution imaging system could be an important asset for in vivo psychiatric research by combining structural and molecular information.

Relationship between cognitive insight and subjective quality of life in outpatients with schizophrenia

BACKGROUND

The concept of cognitive insight refers to the cognitive processes involved in patients' re-evaluation of their anomalous experiences and of their misinterpretations. The purpose of the present study was to examine the relationship between cognitive insight and subjective quality of life in patients with schizophrenia to further shed light on the nature of cognitive insight and its functional correlates in schizophrenia.

METHODS

Seventy-one stable outpatients with schizophrenia were evaluated for cognitive insight and subjective quality of life using the Beck Cognitive Insight Scale (BCIS) and the Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4). The symptoms of schizophrenia were also assessed. Pearson's correlation analysis and partial correlation analysis that controlled for the severity of symptoms were performed to adjust for the possible effects of symptoms.

RESULTS

The self-reflectiveness subscale score of the BCIS had significant positive correlations with the SQLS-R4 psychosocial domain and total SQLS-R4 scores, indicating that the higher the level of cognitive insight, the lower the subjective quality of life. In partial correlation analysis controlling for symptoms, the BCIS self-reflectiveness subscale score still had a significant correlation with the SQLS-R4 psychosocial domain score. The correlation coefficient between the BCIS self-reflectiveness and total SQLS-R4 scores was reduced to a nonsignificant statistical tendency.

CONCLUSION

The results of our study suggest that cognitive insight, particularly the level of self-reflectiveness, is negatively associated with the level of subjective quality of life in outpatients with schizophrenia and that this relationship is not wholly due to the confounding effect of symptoms. Future studies are necessary to explore possible mediating and moderating factors and to evaluate the effects of therapeutic interventions on the relationship.

Long-term efficacy and safety of blonanserin in patients with first-episode schizophrenia: a 1-year open-label trial

AIMS

The purpose of this study was to evaluate the long-term effectiveness and safety of blonanserin, a second-generation antipsychotic drug developed in Japan, in patients with first-episode schizophrenia.

METHODS

Twenty-three antipsychotic-naïve patients with first-episode schizophrenia were treated within an open-label, 1-year, prospective trial of blonanserin (2-24 mg/day). Clinical evaluations were conducted at baseline and 2, 6, and 12 months after the start of treatment. The main outcome measures were changes in subjective well-being and subjective quality of life, as assessed by the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version and the Schizophrenia Quality of Life Scale-Japanese version, respectively. Secondary outcome measures included the Positive and Negative Syndrome Scale, the Brief Assessment of Cognition in Schizophrenia-Japanese version, laboratory tests, bodyweight, and extrapyramidal symptoms.

RESULTS

Fourteen patients (60.9%) remained on the study at 1 year. In the intention-to-treat analysis, significant improvements were observed in several subscales on the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version, the Schizophrenia Quality of Life Scale-Japanese version, and the Brief Assessment of Cognition in Schizophrenia-Japanese version, and in all factor scores on the Positive and Negative Syndrome Scale. Improvement in depressive symptoms with blonanserin treatment was positively correlated with improvements in subjective well-being and subjective quality of life, as well as verbal memory. No significant changes were noted for any safety measure during the 1-year study period.

CONCLUSIONS

Blonanserin was well tolerated and effective for the treatment of first-episode schizophrenia in terms of subjective wellness, cognition, and a wide range of pathological symptoms. Further large-scale studies are warranted to confirm our findings.

Is the PANSS cognitive scale measuring cognition?

OBJECTIVE

To investigate the association between the Positive and Negative Syndrome Scale (PANSS) cognitive factors and cognition assessed by neuropsychological tests.

METHOD

Ninety patients with a psychotic illness, the majority having a schizophrenia diagnosis, were assessed with PANSS ratings and tested by a comprehensive computerized neuropsychological test battery, EuCog.

RESULTS

Test performance was in the normal range for some of the cognitive indices, but substantially reduced for others, compared with norms, particularly speed-based indices. PANSS ratings were non-specifically associated with cognitive indices representing performance (speed and accuracy) and problem solving strategies (executive functions). There was no discriminant validity for the cognitive factor. A regression analysis suggested that the PANSS cognitive factors reflected verbal IQ but no other cognitive domain like memory, attention or speed.

CONCLUSION

Cognitive test performance is associated with psychopathology as assessed by PANSS items but in a non-specific way. The PANSS cognitive subscale seems to reflect over-learned verbal skills rather than the cognitive domains, which are known to be specifically affected in schizophrenia and relevant for the prognosis. Consequently, PANSS ratings cannot replace the information inherent in neuropsychological test data. The extensive speed problem of patients with schizophrenia should be studied in more detail using test batteries that focus on that problem.

A cross-national factor analytic comparison of three models of PANSS symptoms in schizophrenia

The 30-item Positive and Negative Syndrome Scale (PANSS) is used worldwide in the assessment of symptom severity in schizophrenia. The present study uses confirmatory factor analysis (CFA) to compare three different factorial models and to evaluate the best-fitting representation of schizophrenia symptom structure on the PANSS across four samples of patients diagnosed with schizophrenia from the US (the CATIE schizophrenia trial), São Paulo, Brazil, and from Beijing and Changsha, China. We examine the goodness of fit of several previously proposed models. The traditional trifactorial model for the PANSS and two five-factor models were evaluated using absolute and incremental indices. Single group CFA found that the five-factor model proposed by NIMH researchers based on an extensive literature review demonstrates the best fit in each of the four samples. This model used 20 of the 30 PANSS items grouped into five factors: positive, negative, disorganized, excited, and depressed symptoms. Subgroups defined by age, gender, nationality, hospitalization status, and severity of illness also did not differ in overall symptom structure as assessed by several standard indices. Our findings suggest that the five factor NIMH model showed the best representation among all four samples from different countries and potentially contrasting cultures.

Association between subjective well-being and depressive symptoms in treatment-resistant schizophrenia before and after treatment with clozapine

BACKGROUND

We examined the relationship between subjective well-being and depressive symptoms in patients with treatment-resistant schizophrenia before and after treatment with clozapine to contribute to the growing body of research regarding the determinants of patients' perspective of their own well-being in schizophrenia.

METHODS

Forty patients with treatment-resistant schizophrenia were comprehensively evaluated for subjective well-being, schizophrenic symptoms, and depressive symptoms before and 8 weeks after the initiation of treatment with clozapine. Correlation analysis and Fisher's z-transformation statistics were performed.

RESULTS

There were significant improvements in all Positive and Negative Syndrome Scale (PANSS) factor scores and Beck Depression Inventory (BDI) score over the treatment period (P<.05). Before clozapine administration, the subjective well-being score had significant negative correlations with the PANSS depression factor score (P<.05) and the BDI score (P<.05). After clozapine treatment, the subjective well-being score still had significant negative correlations with the PANSS depression factor score (P<.05) and the BDI score (P<.05) and no new associations emerged with treatment. Fisher's z-transformation statistics revealed that the correlations between the subjective well-being score and the depression score were not significantly different before and after clozapine treatment.

CONCLUSIONS

These results indicate that depressive symptoms are significantly associated with low subjective well-being in patients with treatment-resistant schizophrenia. The association was equally significant before and after treatment with clozapine, suggesting that the relationship does not change with clozapine treatment, even when depressive symptoms improve significantly, and that there may be a common pathophysiological basis for depressive symptoms and the subjective appraisal of well-being in schizophrenia.

Identification of psychopathological course trajectories in schizophrenia

Course trajectory analyses have been performed primarily for treatment response in acute episodes of schizophrenic disorders. As yet, corresponding data for the long-term course are lacking. Within a multicenter prospective observational study, 268 patients with schizophrenia were assessed at discharge from hospital and followed up after 6, 12, 18, and 24 months. A latent class growth analysis was performed on the scores from the Positive and Negative Syndrome Scale (PANSS). A two-class conditional latent class model showed the best data fit (Entropy: 0.924). The model divided the sample into a group with amelioration in all PANSS subscales (60%) and a group with stable positive/negative and deteriorating general psychopathology symptoms (40%). Global functioning (GAF score), gender, age, living situation and involuntary admission predicted course trajectory class membership. The model was predictive of significant differences between the two groups in health care service costs and quality of life. The results underline the heterogeneous course of the illness, which ranged from amelioration to deterioration over a 2-year period. Statistical models such as trajectory analysis could help to identify more homogenous subtypes in schizophrenia.

A new Integrated Negative Symptom structure of the Positive and Negative Syndrome Scale (PANSS) in schizophrenia using item response analysis

BACKGROUND

Debate persists with regard to how best to categorize the syndromal dimension of negative symptoms in schizophrenia. The aim was to first review published Principle Components Analysis (PCA) of the PANSS, and extract items most frequently included in the negative domain, and secondly, to examine the quality of items using Item Response Theory (IRT) to select items that best represent a measurable dimension (or dimensions) of negative symptoms.

METHODS

First, 22 factor analyses and PCA met were included. Second, using a large dataset (n=7187) of participants in clinical trials with chronic schizophrenia, we extracted items loading on one or more PCA. Third, items not loading with a value of ≥ 0.5, or loading on more than one component with values of ≥ 0.5 were discarded. Fourth, resulting items were included in a non-parametric IRT and retained based on Option Characteristic Curves (OCCs) and Item Characteristic Curves (ICCs).

RESULTS

15 items loaded on a negative domain in at least one study, with Emotional Withdrawal loading on all studies. Non-parametric IRT retained nine items as an Integrated Negative Factor: Emotional Withdrawal, Blunted Affect, Passive/Apathetic Social Withdrawal, Poor Rapport, Lack of Spontaneity/Conversation Flow, Active Social Avoidance, Disturbance of Volition, Stereotyped Thinking and Difficulty in Abstract Thinking.

CONCLUSIONS

This is the first study to use a psychometric IRT process to arrive at a set of negative symptom items. Future steps will include further examination of these nine items in terms of their stability, sensitivity to change, and correlations with functional and cognitive outcomes.

Association of serotonin transporter gene (SLC6A4) polymorphisms with schizophrenia susceptibility and symptoms in a Chinese-Han population

Schizophrenia (SZ) is a complex psychiatric disorder with a strong genetic component. The serotonin transporter (SERT), encoded by solute carrier family 6 member 4 (SLC6A4), regulates synaptic concentrations of serotonin and thereby strongly influences perception, mood, emotion, behavior, and cognition, all of which are severely disturbed in SZ. Two variable numbers of tandem repeat (VNTR) polymorphisms and several single nucleotide polymorphisms (SNPs) spread throughout SLC6A4 are involved in both neuropsychiatric diseases (including SZ) and personality traits. In this study, case-control association analysis was performed in the Chinese-Han population to identify additional allelic variants of the SLC6A4 gene that may confer susceptibility to SZ. Ten relatively common SNPs (minor allele frequency >5%) were genotyped in 528 paranoid SZ patients and 528 control subjects. Significant associations were found between SZ and the allele and genotypic frequencies of rs140700G/A (p=2.45×10(-12), 2.34×10(-11), respectively). The frequency of the A allele was lower in SZ patients (17.7%) than in controls (30.9%; OR=1.93, 95%CI=1.58-2.36). In five factor analysis of the positive and negative syndrome scale (PANSS) scores of first episode SZ patients, mean negative factor score (F2,249=3.986, p=0.02) and depression/anxiety factor score (F2, 249=8.766, p=2.11×10(-4)) were significantly different among the rs140700G/A genotypes, with both scores higher for genotype AA than AG+GG. The rs140700G/A allele of SLC6A4 is strongly associated with SZ susceptibility and symptom expression in the Chinese-Han population.

Validated five-factor model of positive and negative syndrome scale for schizophrenia in Chinese population

The Positive and Negative Syndrome Scale (PANSS) is the most widely used instrument to assess the severity of symptoms of schizophrenia. Most studies have showed that PANSS measures five dimensions of symptomatology of schizophrenia. However, few studies have ever investigated the structure of PANSS in Chinese schizophrenia population. We recruited two large independent study samples including 903 and 942 Chinese schizophrenia patients and examined the underlying structure of PANSS. By building a confirmatory factor analysis (CFA) model based on the factor loadings of the exploratory factor analysis (EFA) and by testing the CFA model in an independent validation sample, we found that PANSS scores consisted of five factors, which were positive factor, negative factor, excitement factor, depression factor, and cognitive factor. The items loaded on these factors were similar to the consensus items published in previous studies except for PANSS items P2 conceptual disorganization, P5 grandiosity, N5 abstract thinking, and G11 poor attention. This difference might be due to the influence of culture on clinical presentation of schizophrenia. By elucidating the structure, symptoms of Chinese schizophrenia patients could possibly be deconstructed and investigated in future studies.