Advances in the understanding of the pathophysiology of schizophrenia and bipolar disorder through induced pluripotent stem cell models.

The pathophysiology of schizophrenia and bipolar disorder involves a complex interaction between genetic and environmental factors that begins in the early stages of neurodevelopment. Recent advancements in the field of induced pluripotent stem cells (iPSCs) offer a promising tool for understanding the neurobiological alterations involved in these disorders and, potentially, for developing new treatment options. In this review, we summarize the results of iPSC-based research on schizophrenia and bipolar disorder, showing disturbances in neurodevelopmental processes, imbalance in glutamatergic-GABAergic transmission and neuromorphological alterations. The limitations of the reviewed literature are also highlighted, particularly the methodological heterogeneity of the studies, the limited number of studies developing iPSC models of both diseases simultaneously, and the lack of in-depth clinical characterization of the included samples. Further studies are needed to advance knowledge on the common and disease-specific pathophysiological features of schizophrenia and bipolar disorder and to promote the development of new treatment options.

The Autism Rating Scale for Schizophrenia - Revised English Version: An Instrument to Characterize Schizophrenia Spectrum Disorders Phenotype.

Dis-sociality (DS) reflects the impairment of social experience in people with schizophrenia; it encompasses both negative features (disorder of attunement, inability to grasp the meaning of social contexts, the vanishing of social shared knowledge) and positive features (a peculiar set of values, ruminations not oriented to reality), reflecting the existential arrangement of people with schizophrenia. DS is grounded on the notion of schizophrenic autism as depicted by continental psychopathology. A rating scale has been developed, providing an experiential phenotype. Here we present the Autism Rating Scale for Schizophrenia - Revised English version (ARSS-Rev), developed on the Italian version of the scale. The scale is provided by a structured interview to facilitate the assessment of the phenomena investigated here. ARSS-Rev is composed of 16 distinctive items grouped into 6 categories: hypo-attunement, invasiveness, emotional flooding, algorithmic conception of sociality, antithetical attitude toward sociality, and idionomia. For each item and category, an accurate description is provided. Different intensities of phenomena are assessed through a Likert scale by rating each item according to its quantitative features (frequency, intensity, impairment, and need for coping). The ARSS-Rev has been able to discriminate patients with remitted schizophrenia from euthymic patients with psychotic bipolar disorder. This instrument may be useful in clinical/research settings to demarcate the boundaries of schizophrenia spectrum disorders from affective psychoses.

Long-Term Efficacy and Safety of Paliperidone 6-Month Formulation: An Open-Label 2-Year Extension of a 1-Year Double-Blind Study in Adult Participants With Schizophrenia.

BACKGROUND: Paliperidone palmitate 6-month (PP6M) demonstrated noninferiority to paliperidone palmitate 3-month in preventing relapse in patients with schizophrenia in a phase 3 double-blind (DB) study (NCT03345342). Here, we report long-term efficacy and safety results from a 2-year single-arm, open-label extension (OLE; NCT04072575) of this DB study. METHODS: Participants who completed the DB study without relapse were enrolled and followed-up every 3 months up to 2 years. Participants received 4 PP6M gluteal injections (700/1000 mg eq.) at baseline, 6-month, 12-month, and 18-month visits. Efficacy endpoints included assessment of relapse, Positive and Negative Syndrome Scale total score, Personal and Social Performance score, and Clinical Global Impression-Severity scale change from baseline. Safety was assessed by treatment-emergent adverse events (TEAEs), physical examinations, and laboratory tests. RESULTS: Of 178 participants enrolled, 154 (86.5%) completed the OLE (mean age: 40.4 years, men: 70.8%; mean duration of PP6M exposure during OLE: 682.1 days). Overall, 7/178 (3.9%) participants relapsed between 20 and 703 days after enrolment. Mean (SD) changes from baseline to endpoint were as follows: Positive and Negative Syndrome Scale total score, 0.7 (8.22); Clinical Global Impression-Severity, 0.0 (0.51); and Personal and Social Performance Scale, 0.5 (7.47). Overall, 111/178 participants (62.4%) reported ≥1 TEAE; most common (>5%) TEAEs were headache (13.5%) and increased blood prolactin/hyperprolactinemia (18.0%); 8/178 (4.5%) participants experienced serious TEAEs, and 6/178 (3.4%) participants withdrew due to TEAEs. No deaths were reported. CONCLUSIONS: The relapse rate observed with PP6M during the 2-year OLE was low (3.9%). Clinical and functional improvements demonstrated in the DB study were maintained during OLE, and no new safety concerns were identified. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04072575; EudraCT number: 2018-004532-30.

The pathophysiology of negative symptoms of schizophrenia: main hypotheses and open challenges.

Important developments in the conceptualisation and classification of negative symptoms have contributed to refining hypotheses on their pathophysiology. The uptake of recent progress is still only partial and the whole field might make a leap forward once relevant studies fully make use of assessment tools based on current conceptualisations.

Negative symptoms in First-Episode Schizophrenia related to morphometric alterations in orbitofrontal and superior temporal cortex: the OPTiMiSE study.

BACKGROUND: Negative symptoms are one of the most incapacitating features of Schizophrenia but their pathophysiology remains unclear. They have been linked to alterations in grey matter in several brain regions, but findings have been inconsistent. This may reflect the investigation of relatively small patient samples, and the confounding effects of chronic illness and exposure to antipsychotic medication. We sought to address these issues by investigating concurrently grey matter volumes (GMV) and cortical thickness (CTh) in a large sample of antipsychotic-naïve or minimally treated patients with First-Episode Schizophrenia (FES). METHODS: T1-weighted structural MRI brain scans were acquired from 180 antipsychotic-naïve or minimally treated patients recruited as part of the OPTiMiSE study. The sample was stratified into subgroups with (N = 88) or without (N = 92) Prominent Negative Symptoms (PMN), based on PANSS ratings at presentation. Regional GMV and CTh in the two groups were compared using Voxel-Based Morphometry (VBM) and FreeSurfer (FS). Between-group differences were corrected for multiple comparisons via Family-Wise Error (FWE) and Monte Carlo z-field simulation respectively at p < 0.05 (2-tailed). RESULTS: The presence of PMN symptoms was associated with larger left inferior orbitofrontal volume (p = 0.03) and greater CTh in the left lateral orbitofrontal gyrus (p = 0.007), but reduced CTh in the left superior temporal gyrus (p = 0.009). CONCLUSIONS: The findings highlight the role of orbitofrontal and temporal cortices in the pathogenesis of negative symptoms of Schizophrenia. As they were evident in generally untreated FEP patients, the results are unlikely to be related to effects of previous treatment or illness chronicity.

Clinical and psychological factors associated with resilience in patients with schizophrenia: data from the Italian network for research on psychoses using machine learning.

BACKGROUND: Resilience is defined as the ability to modify thoughts to cope with stressful events. Patients with schizophrenia (SCZ) having higher resilience (HR) levels show less severe symptoms and better real-life functioning. However, the clinical factors contributing to determine resilience levels in patients remain unclear. Thus, based on psychological, historical, clinical and environmental variables, we built a supervised machine learning algorithm to classify patients with HR or lower resilience (LR). METHODS: SCZ from the Italian Network for Research on Psychoses (N = 598 in the Discovery sample, N = 298 in the Validation sample) underwent historical, clinical, psychological, environmental and resilience assessments. A Support Vector Machine algorithm (based on 85 variables extracted from the above-mentioned assessments) was built in the Discovery sample, and replicated in the Validation sample, to classify between HR and LR patients, within a nested, Leave-Site-Out Cross-Validation framework. We then investigated whether algorithm decision scores were associated with the cognitive and clinical characteristics of patients. RESULTS: The algorithm classified patients as HR or LR with a Balanced Accuracy of 74.5% (p < 0.0001) in the Discovery sample, and 80.2% in the Validation sample. Higher self-esteem, larger social network and use of adaptive coping strategies were the variables most frequently chosen by the algorithm to generate decisions. Correlations between algorithm decision scores, socio-cognitive abilities, and symptom severity were significant (pFDR < 0.05). CONCLUSIONS: We identified an accurate, meaningful and generalizable clinical-psychological signature associated with resilience in SCZ. This study delivers relevant information regarding psychological and clinical factors that non-pharmacological interventions could target in schizophrenia.

Insight in cognitive impairment assessed with the Cognitive Assessment Interview in a large sample of patients with schizophrenia.

The Cognitive Assessment Interview (CAI) is an interview-based scale measuring cognitive impairment and its impact on functioning in subjects with schizophrenia (SCZ). The present study aimed at assessing, in a large sample of SCZ (n = 601), the agreement between patients and their informants on CAI ratings, to explore patients' insight in their cognitive deficits and its relationships with clinical and functional indices. Agreement between patient- and informant-based ratings was assessed by the Gwet's agreement coefficient. Predictors of insight in cognitive deficits were explored by stepwise multiple regression analyses. Patients reported lower severity of cognitive impairment vs. informants. A substantial to almost perfect agreement was observed between patients' and informants' ratings. Lower insight in cognitive deficits was associated to greater severity of neurocognitive impairment and positive symptoms, lower severity of depressive symptoms, and older age. Worse real-life functioning was associated to lower insight in cognitive deficit, worse neurocognitive performance, and worse functional capacity. Our findings indicate that the CAI is a valid co-primary measure with the interview to patients providing a reliable assessment of their cognitive deficits. In the absence of informants with good knowledge of the subject, the interview to the patient may represent a valid alternative.

Achieving long-term goals through early personalized management of schizophrenia: expert opinion on the role of a new fast-onset long-acting injectable antipsychotic.

Definition of an appropriate and personalized treatment plan focused on long-term outcomes is crucial in the management of schizophrenia. Following review of the literature, a panel of six leading psychiatrists discussed the importance of clear and shared long-term goals when initiating antipsychotic treatment in light of their clinical experience. The importance of establishing shared and progressive treatment objectives was stressed, which should be tailored based on the patient's characteristics, goals, and preferences. Consensus emerged on the key role that therapeutic alliance and patient empowerment play throughout the course of treatment. Reduction in symptoms in the acute phase along with good efficacy and tolerability in the maintenance phase emerged as essential features of a therapy that can favor achievement of long-term outcomes. Long-acting injectable (LAI) antipsychotics enhance adherence to treatment compared to oral formulations and have been shown to be effective in the maintenance phase. Currently available LAIs are characterized by a delayed onset of action and require a loading dose or oral supplementation to achieve therapeutic concentrations. Risperidone ISM® is a novel LAI antipsychotic with fast and sustained release of antipsychotic, reaching therapeutic plasma levels within a few hours after administration without oral supplementation or loading doses. Risperidone ISM® has been shown to rapidly control symptoms in patients with an acute exacerbation of schizophrenia and to be effective and well tolerated as maintenance treatment irrespective of the severity of initial symptoms. It thus represents a valuable and novel therapeutic option in management of schizophrenia.

A Randomized, Double-Blind, Multicenter, Noninferiority Study Comparing Paliperidone Palmitate 6-Month Versus the 3-Month Long-Acting Injectable in Patients With Schizophrenia.

BACKGROUND: This double-blind (DB), randomized, parallel-group study was designed to evaluate efficacy and safety of paliperidone palmitate 6-month (PP6M) formulation relative to paliperidone palmitate 3-month (PP3M) formulation in patients with schizophrenia. METHODS: Following screening, patients entered an open-label (OL) maintenance phase and received 1 injection cycle of paliperidone palmitate 1-month (PP1M; 100 or 150 mg eq.) or PP3M (350 or 525 mg eq.). Clinically stable patients were randomized (2:1) to receive PP6M (700 or 1000 mg eq., gluteal injections) or PP3M (350 or 525 mg eq.) in a 12-month DB phase; 2 doses of PP6M (corresponding to doses of PP1M and PP3M) were chosen. RESULTS: Overall, 1036 patients were screened, 838 entered the OL phase, and 702 (mean age: 40.8 years) were randomized (PP6M: 478; PP3M: 224); 618 (88.0%) patients completed the DB phase (PP6M: 416 [87.0%]; PP3M: 202 [90.2%]). Relapse rates were PP6M, 7.5% (n = 36) and PP3M, 4.9% (n = 11). The Kaplan-Meier estimate of the difference (95% CI) between treatment groups (PP6M - PP3M) in the percentages of patients who remained relapse free was -2.9% (-6.8%, 1.1%), thus meeting noninferiority criteria (95% CI lower bound is larger than the pre-specified noninferiority margin of -10%). Secondary efficacy endpoints corroborated the primary analysis. Incidences of treatment-emergent adverse events were similar between PP6M (62.1%) and PP3M (58.5%). No new safety concerns emerged. CONCLUSIONS: The efficacy of a twice-yearly dosing regimen of PP6M was noninferior to that of PP3M in preventing relapse in patients with schizophrenia adequately treated with PP1M or PP3M. TRIAL REGISTRATION: Clinical Trials.gov identifier: NCT03345342.

Scalability of the Positive and Negative Syndrome Scale in first-episode schizophrenia assessed by Rasch models.

OBJECTIVE: Historically, assessment of the psychometric properties of the Positive and Negative Syndrome Scale (PANSS) has had several foci: (1) calculation of reliability indexes, (2) extraction of subdimensions from the scale, and (3) assessment of the validity of the total score. In this study, we aimed to examine the scalability and to assess the clinical performance of the 30-item PANSS total score as well as the scalability of a shorter version (PANSS-6) of the scale. METHODS: A composite data set of 1073 patients with first-episode schizophrenia or schizophrenia spectrum disorder was subjected to Rasch analysis of PANSS data from baseline and 4-6 weeks follow-up. RESULTS: The central tests of fit of the Rasch model failed to satisfy the statistical requirements behind item homogeneity for the PANSS-30 as well as the PANSS-6 total score. For the PANSS-30, Differential Item Functioning was pronounced both for the 7-point Likert scale rating categories and when dichotomizing the rating categories. Subsequently, the Rasch structure analysis in the context of dichotomized items was used to isolate and estimate a systematic error because of item inhomogeneity, as well as a random error. The size of the combined sources of error for the PANSS-30 total score approximated 20% which is often regarded as clinical cut-off between response versus no-response. CONCLUSION: The results demonstrate the operational consequences of a lack of statistical fit of the Rasch model and suggest that the calculated measure of uncertainty needs to be considered when using the PANSS-30 total score.

Factors influencing lithium versus valproate prescription preference in the maintenance treatment of bipolar patients: a report from the Italian Early Career Psychiatrists (SOPSI-GG).

BACKGROUND: Objective of the present manuscript is to investigate, among Italian early career psychiatrists (ECPs), prescriber and patient-related factors associated with lithium or valproate preference to treat patients affected by Bipolar Disorder (BD). METHODS: An on-line survey was carried out among 252 ECPs, investigating their prescription patterns in relation to lithium and the differences with prescription of valproate. Collected data were compared according to lithium or valproate prescription preference in the long-term treatment of BD by χ2 tests for qualitative variables. RESULTS: Over two thirds of ECPs preferred lithium over valproate for the maintenance treatment of BD. Less than half of the sample used lithium as first-line agent for mania or major depression, and less than one third for mixed episodes. Factors associated with lithium preference as first-line maintenance treatment include perception of having a good knowledge of lithium (p < 0.001) and complete satisfaction with education on lithium (p < 0.001). One of the main factors to prefer valproate was the concern about long-term side effects of lithium (p < 0.001). CONCLUSIONS: Type of education, source of information, clinical experience and safety concerns influence the choice of lithium versus valproate in the long-term treatment of BD. Present findings may guide educational training of ECPs.KEY POINTSLithium has been less prescribed in the last years for long-term treatment of Bipolar Disorder.Educational and clinical factors seem to influence the attitude to prescribe lithium.Only half of the Italian early career psychiatrists declare to have at least an adequate knowledge of lithium.Residency program in psychiatry should consider the implementation of education on lithium.

Die "Präzisionspsychiatrie" muss Teil der "personalisierten Psychiatrie" werden.

'Precision medicine' is defined as 'an emerging approach for treatment and prevention that takes into account each person's variability in genes, environment, and lifestyle'. Sometimes the term 'personalized medicine' is also used, either as a synonym or in a broader sense. In psychiatry, the term 'personalized' applies to different levels of health-care provision, such as the service organization and the choice of treatment plans based on the characterization of the individual patient. This approach is already feasible but, currently, it is often hampered by the shortage of human and financial resources. Recently, the terminology of 'precision medicine' has been extended to psychiatry: the term 'precision psychiatry' refers to the full exploitation of recent scientific and technological advances to achieve a close match between individual biosignature and prevention / treatment strategies. This article provides an overview of recent advances in neuroimaging, multi-omics and computational neuroscience, which have contributed to foster our understanding of the neurobiology of major mental disorders, and led to the implementation of a precision medicine-oriented approach in psychiatry.We argue that, while 'precision psychiatry' represents an important step to further advance the effectiveness of the 'personalized psychiatry', the distinction between the two terms is important to avoid dangerous neglect of the current potential of personalized care in psychiatry and to underscore the need for disseminating good existing practices aimed at organizing mental health services and providing care according to person's psychopathological characteristics, illness trajectory, needs, environment and preferences.In conclusion, 'precision psychiatry' will contribute to advance 'personalized psychiatry', but for the time being keeping the distinction between the two terms will contribute to fully exploit the current potential of personalized care.

Questionnaire on Attitude towards Research and Care (QuARC): a survey of patients with psychosis.

Background: The patients' appraisal, satisfaction and attitude toward research is crucial to obtain reliable information, in psychiatry frequently not objective.Aim: We operationalised the information derived from studies on satisfaction and attitude towards research and developed a standardized measure, whose internal consistency and factor structure was investigated.Method: The Questionnaire on Attitude towards Research and health Care (QuARC) is a 10-item self-report scale, administered to 116 patients with psychotic disorders participating in research protocols. Exploratory factor analysis was conducted and internal consistency evaluated.Results: Two factors have been identified: one labelled External Factor, including items related to information on the received treatment, relationship with third parties, and one labelled Internal Factor with items related to the disorder, perceived well-being and contribution to scientific knowledge. Cronbach's alpha internal consistencies were good.Conclusions: The QuARC is easy to use, well accepted, with good psychometric properties. The constructs identified are different from the original issues addressed (i.e. attitude and satisfaction), prevailing different constructs closer to the patient opinion on the research and personal condition. These constructs identify dimensions useful to delineate and understand the patients' experience of participating in a scientific project as well as their satisfaction.

The relationships of personal resources with symptom severity and psychosocial functioning in persons with schizophrenia: results from the Italian Network for Research on Psychoses study.

The relationships of personal resources with symptom severity and psychosocial functioning have never been tested systematically in a large sample of people with schizophrenia. We applied structural equation models to a sample of 921 patients with schizophrenia collected in a nationwide Italian study, with the aim to identify, among a large set of personal resources, those that may have an association with symptom severity or psychosocial functioning. Several relevant demographic and clinical variables were considered concurrently. Poor service engagement and poor recovery style, as well as older age and younger age at onset, were related to greater symptom severity and poorer social functioning. Higher resilience and higher education were related to better social functioning only. Poor problem-focused coping and internalized stigma, as well as male gender and depression, were related to symptom severity only. The explored variables showed distinctive and partially independent associations with symptom severity and psychosocial functioning. A deeper understanding of these relationships may inform treatment decisions.

Neurobiological background of negative symptoms.

Studies investigating neurobiological bases of negative symptoms of schizophrenia failed to provide consistent findings, possibly due to the heterogeneity of this psychopathological construct. We tried to review the findings published to date investigating neurobiological abnormalities after reducing the heterogeneity of the negative symptoms construct. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, genetics and neurobiology of schizophrenia. We searched PubMed with the keywords "negative symptoms," "deficit schizophrenia," "persistent negative symptoms," "neurotransmissions," "neuroimaging" and "genetic." Additional articles were identified by manually checking the reference lists of the relevant publications. Publications in English were considered, and unpublished studies, conference abstracts and poster presentations were not included. Structural and functional imaging studies addressed the issue of neurobiological background of negative symptoms from several perspectives (considering them as a unitary construct, focusing on primary and/or persistent negative symptoms and, more recently, clustering them into factors), but produced discrepant findings. The examined studies provided evidence suggesting that even primary and persistent negative symptoms include different psychopathological constructs, probably reflecting the dysfunction of different neurobiological substrates. Furthermore, they suggest that complex alterations in multiple neurotransmitter systems and genetic variants might influence the expression of negative symptoms in schizophrenia. On the whole, the reviewed findings, representing the distillation of a large body of disparate data, suggest that further deconstruction of negative symptomatology into more elementary components is needed to gain insight into underlying neurobiological mechanisms.

Comparing the World Psychiatric Association and European Psychiatric Association Codes of Ethics: Discrepancies and shared grounds.

BACKGROUND: Codes of ethics provide guidance to address ethical challenges encountered in clinical practice. The harmonization of global, regional, and national codes of ethics is important to avoid gaps and discrepancies. METHODS: We compare the European Psychiatric Association (EPA) and the World Psychiatric Association (WPA) Codes of Ethics, addressing main key points, similarities, and divergences. RESULTS: The WPA and EPA codes are inspired by similar fundamental values but do show a few differences. The two codes have a different structure. The WPA code includes 4 sections and lists 5 overarching principles as the basis of psychiatrists' clinical practice; the EPA code is articulated in 8 sections, lists 4 ethical principles, and several fundamental values. The EPA code does not include a section on psychiatrists' education and does not contain specific references to domestic violence and death penalty. Differences can be found in how the two codes address the principle of equity: the EPA code explicitly refers to the principle of universal health care, while the WPA code mentions the principle of equity as reflected in the promotion of distributive justice. CONCLUSIONS: We recommend that both WPA and EPA periodically update their ethical codes to minimize differences, eliminate gaps, and help member societies to develop or revise national codes in line with the principles of the associations they belong to.Minimizing differences between national and international codes and fostering a continuous dialogue on ethical issues will provide guidance for psychiatrists and will raise awareness of the importance of ethics in our profession.

Definition, assessment and treatment of cognitive impairment associated with schizophrenia: expert opinion and practical recommendations.

A considerable proportion of patients with schizophrenia perform below population norms on standardized neuropsychological tests, and the performance of those performing within normal range is lower than predicted based on parental education. Cognitive impairment predates the onset of psychosis, is observed during symptom remission and in non-affected first-degree relatives of patients. At the present time, cognitive deficits are regarded as key features of schizophrenia, important determinants of poor psychosocial outcome and targets for both pharmacological and non-pharmacological treatment strategies. A group of eight key opinion leaders reviewed and discussed latest advances in scientific research and current good clinical practices on assessment, management, and treatment of CIAS. In the present paper they summarize the current evidence, identify main gaps between current knowledge and mental health services clinical practice, and provide practical recommendations to reduce the gap.

Identification and treatment of individuals with childhood-onset and early-onset schizophrenia.

Approximately 8 % of patients with schizophrenia are diagnosed before age 18, and 18 % experience their first symptoms before age 18. This narrative review explores the management of patients with early-onset schizophrenia (EOS) and childhood-onset schizophrenia (COS) from diagnosis to their transition to adult care settings. Early diagnosis of schizophrenia in children and adolescents is essential for improving outcomes, but delays are common due to overlapping of symptoms with developmental phenomena and other psychiatric conditions, including substance use, and lack of clinicians' awareness. Once diagnosed, antipsychotic treatment is key, with specific second-generation agents generally being preferred due to better tolerability and their broader efficacy evidence-base in youth. Dosing should be carefully individualized, considering age-related differences in drug metabolism and side effect liability. Clinicians must be vigilant in detecting early non-response and consider switching or dose escalation when appropriate. Since early age of illness onset is a consistent risk factor for treatment-resistant schizophrenia (TRS), clinicians need to be competent in diagnosing TRS and using clozapine. Since COS and EOS are associated with cognitive deficits and impaired functioning, psychosocial interventions should be considered to improve overall functioning and quality of life. Good long-term outcomes depend on continuous treatment engagement, and successful transitioning from pediatric to adult care requires careful planning, early preparation, and collaboration between pediatric and adult clinicians. Targeting functional outcomes and quality of life in addition to symptom remission can improve overall patient well-being. Comprehensive evaluations, age-specific assessments, and targeted interventions are needed to address the unique challenges of EOS and COS.

Clinician-Reported Negative Symptom Scales: A Systematic Review of Measurement Properties.

BACKGROUND: Negative symptoms of schizophrenia are correlated with reduction of normal function and lower quality of life. They were newly defined by the NIMH-MATRICS Consensus in 2005, dividing the rating tools to assess them into first-generation scales, developed before the Consensus, and second-generation scales, based on the recently introduced definitions. METHODS: The COnsensus-based Standards for the selection of health Measurement Instrument (COSMIN) guidelines for systematic reviews were used to evaluate the quality of psychometric data of the first-generation scales that cover the 5 negative symptom domains of the NIMHS Consensus: the Scale for the Assessment of Negative Symptoms (SANS), the High Royds Evaluation of Negativity Scale (HEN), and the Negative Symptom Assessment-16 (NSA-16). RESULTS: The search strategy resulted in the inclusion of a total of 13 articles, 7 for the SANS, 4 for the NSA-16, and 2 for the HEN. For the SANS and the NSA-16, the overall results of the scales' measurement properties are mostly insufficient or indeterminate. The quality of evidence for the HEN is poor, due to a small number of validation studies/included patients. CONCLUSIONS: After applying the COSMIN guidelines, we do not recommend the usage of these first-generation scales to rate negative symptoms. At the minimum they require further validation.

The dimensional structure of the Positive and Negative Syndrome Scale in first-episode schizophrenia spectrum disorders: an Exploratory Graph Analysis from the OPTiMiSE trial.

The Positive and Negative Syndrome Scale (PANSS) is the most widely used rating scale to assess psychotic symptoms in patients with schizophrenia and other primary psychoses. However, a definitive consensus regarding its dimensional structure remains elusive. The present work aims to determine the number of dimensions of the scale through a network analysis approach in a sample of individuals experiencing first-episode schizophrenia spectrum disorder (FE-SSD) with minimal or no prior exposure to antipsychotic treatment. Baseline data of 446 participants (age 25.96 ± 5.99 years, 70% males) enrolled in the OPTiMiSE trial were analysed. Exploratory Graph Analysis (EGA) was conducted to evaluate the dimensionality of the PANSS, and a bootstrap approach (bootEGA) was employed to assess model stability. The analysis was replicated, excluding unstable items with stability values below 0.75, until a stable model was achieved. The analysis of the 30 items of the PANSS revealed inadequate structural consistency, resulting in the exclusion of 9 unstable items. The final model comprised 21 symptoms distributed across four communities (Positive, Cognitive/Disorganised, Excited/Aggressive and Negative) but lacked a depressive domain. In conclusion, we propose a concise version of the PANSS, incorporating 21 items, to better assess the core symptoms of the first episode of SSD. This revised version provides clinicians with a robust psychometric tool with reduced administration time, but the complementary administration of a dedicated instrument for evaluating affective symptoms is advisable.