The brief negative symptom scale (BNSS): Sensitivity to treatment effects

Effects of Adapted Physical Activity on White Matter Integrity in Patients with Schizophrenia

Schizophrenia is associated with changes in white matter (WM) integrity and with reduced life expectancy, in part because of the cardiometabolic side effects of antipsychotics. Physical activity (PA) has emerged as a candidate lifestyle intervention that is safe and effective. The study aimed to assess how an adapted PA program delivered remotely by web (e-APA) improved WM integrity in patients with schizophrenia (SZPs) and healthy controls (HCs) and to evaluate associations among WM integrity, cardiorespiratory fitness, and symptom severity. This longitudinal study was conducted over 16 weeks with 31 participants (18 SZPs and 13 HCs). Diffusion tensor imaging and tract-based spatial statistics were employed to assess WM integrity. Cardiorespiratory fitness was measured by maximal oxygen uptake (VO2max), and assessments for clinical symptoms included the Positive and Negative Syndrome Scale, Self-evaluation of Negative Symptoms and the Brief Negative Syndrome Scale (BNSS). Only the SZPs had significantly increased WM integrity after the e-APA program, with increased fractional anisotropy and decreased radial diffusivity in fasciculi involved in motor functions and language process. Furthermore, decreased negative symptoms assessed with BNSS were associated with greater WM integrity following the program. These findings suggest that e-APA may improve WM integrity abnormalities and support e-APA as a promising therapeutic strategy.

Effects of web-based adapted physical activity on hippocampal plasticity, cardiorespiratory fitness, symptoms, and cardiometabolic markers in patients with schizophrenia: a randomized, controlled study

Among the lifestyle interventions, the physical activity (PA) has emerged as an adjuvant non-pharmacological treatment improving mental and physical health in patients with schizophrenia (SZPs) and increasing the hippocampus (HCP) volume. Previously investigated PA programs have been face-to-face, and not necessary adapted to patients' physiological fitness. We propose an innovative 16-week adapted PA program delivered by real-time videoconferencing (e-APA), allowing SZPs to interact with a coach and to manage their physical condition. The primary goal was to demonstrate a greater increase of total HCP volumes in SZPs receiving e-APA compared to that observed in a controlled group. The secondary objectives were to demonstrate the greater effects of e-APA compared to a controlled group on HCP subfields, cardiorespiratory fitness, clinical symptoms, cognitive functions, and lipidic profile. Thirty-five SZPs were randomized to either e-APA or a controlled group receiving a health education program under the same conditions (e-HE). Variables were assessed at pre- and post-intervention time-points. The dropout rate was 11.4%. Compared to the e-HE group, the e-APA group did not have any effect on the HCP total volumes but increased the left subiculum volume. Also, the e-APA group significantly increased cardiorespiratory fitness (VO2max), improved lipidic profile and negative symptoms but not cognitive functions. This study demonstrated the high feasibility and multiple benefits of a remote e-APA program for SZPs. e-APA may increase brain plasticity and improve health outcomes in SZPs, supporting that PA should be an add-on therapeutic intervention. ClinicalTrial.gov on 25 august 2017 (NCT03261817).

Psychosocial and behavioural interventions for the negative symptoms of schizophrenia: a systematic review of efficacy meta-analyses

BACKGROUND

Currently there is no first-line treatment recommended for the negative symptoms of schizophrenia. Psychosocial and behavioural interventions are widely used to reduce the burden of negative symptoms. Meta-analytic studies have summarised the evidence for specific approaches but not compared evidence quality and benefit.

AIM

To review and evaluate the evidence from meta-analytic studies of psychosocial and behavioural interventions for the negative symptoms of schizophrenia.

METHOD

A systematic literature search was undertaken to identify all meta-analyses evaluating psychosocial and behavioural interventions reporting on negative symptom outcomes in people with schizophrenia. Data on intervention, study characteristics, acceptability and outcome were extracted. Risk of bias was evaluated. Results were summarised descriptively, and evidence ranked on methodological quality.

RESULTS

In total, 31 systematic reviews met the inclusion criteria evaluating the efficacy of negative symptom interventions on 33 141 participants. Exercise interventions showed effect sizes (reduction in negative symptoms) ranging from -0.59 to -0.24 and psychological interventions ranging from -0.65 to -0.04. Attrition ranged between 12% to 32%. Across the studies considered heterogeneity varied substantially (range 0-100). Most of the reviews were of very low to low methodological quality. Methodological quality ranking suggested that the effect size for cognitive remediation and exercise therapy may be more robust compared with other approaches.

CONCLUSIONS

Most of the interventions considered had a small-to-moderate effect size, good acceptability levels but very few had negative symptoms as the primary intervention target. To improve the confidence of these effect sizes being replicated in clinical settings future studies should minimise risk of bias.

Identifying strategies to improve PANSS based dimensional models in schizophrenia: Accounting for multilevel structure, Bayesian model and clinical staging

BACKGROUND

Dimensional approaches can decompose a construct in a set of continuous variables, improving the characterization of complex phenotypes, such as schizophrenia. However, the five-factor model of the Positive and Negative Syndrome Scale (PANSS), the most used instrument in schizophrenia research, yielded poor fits in most confirmatory factor analysis (CFA) studies, raising concerns about its applications. Thus, we aimed to identify dimensional PANSS CFA models with good psychometric properties by comparing the traditional CFA with three methodological approaches: Bayesian CFA, multilevel modeling, and Multiple Indicators Multiple Causes (MIMIC) modeling.

METHODS

Clinical data of 700 schizophrenia patients from four centers were analyzed. We first performed a traditional CFA. Next, we tested the three techniques: 1) a Bayesian CFA; 2) a multilevel analysis using the centers as level; and 3) a MIMIC modeling to evaluate the impact of clinical staging on PANSS factors and items.

RESULTS

CFA and Bayesian CFA produced poor fit models. However, when adding a multilevel structure to the CFA model, a good fit model emerged. MIMIC modeling yielded significant differences in the factor structure between the clinical stages of schizophrenia. Sex, age, age of onset, and duration of illness did not significantly affect the model fit.

CONCLUSION

Our comparison of different CFA methods highlights the need for multilevel structure to achieve a good fit model and the potential utility of staging models (rather than the duration of illness) to deal with clinical heterogeneity in schizophrenia. Large prospective samples with biological data should help to understand the interplay between psychometrics concerns and neurobiology research.

Efficacy and Safety of Roluperidone for the Treatment of Negative Symptoms of Schizophrenia

BACKGROUND

This is a placebo-controlled multi-national trial of roluperidone, a compound with antagonist properties for 5-HT2A, sigma2, and α1A-adrenergic receptors, targeting negative symptoms in patients with schizophrenia. This trial follows a previous trial that demonstrated roluperidone superiority over placebo in a similar patient population.

METHODS

Roluperidone 32 mg/day, roluperidone 64 mg/day, or placebo was administered for 12 weeks to 513 patients with schizophrenia with moderate to severe negative symptoms. The primary endpoint was the PANSS-derived Negative Symptom Factor Score (NSFS) and the key secondary endpoint was Personal and Social Performance scale (PSP) total score.

RESULTS

NSFS scores were lower (improved) for roluperidone 64 mg compared to placebo and marginally missing statistical significance for the intent-to-treat (ITT) analysis data set (P ≤ .064), but reached nominal significance (P ≤ .044) for the modified-ITT (m-ITT) data set. Changes in PSP total score were statistically significantly better on roluperidone 64 mg compared to placebo for both ITT and m-ITT (P ≤ .021 and P ≤ .017, respectively).

CONCLUSIONS

Results of this trial confirm the potential of roluperidone as a treatment of negative symptoms and improving everyday functioning in patients with schizophrenia. Study registration: Eudra-CT: 2017-003333-29; NCT03397134.

Avolition as the core negative symptom in schizophrenia: relevance to pharmacological treatment development

Negative symptoms have long been considered a core component of schizophrenia. Modern conceptualizations of the structure of negative symptoms posit that there are at least two broad dimensions (motivation and pleasure and diminished expression) or perhaps five separable domains (avolition, anhedonia, asociality, blunted affect, alogia). The current review synthesizes a body of emerging research indicating that avolition may have a special place among these dimensions, as it is generally associated with poorer outcomes and may have distinct neurobiological mechanisms. Network analytic findings also indicate that avolition is highly central and interconnected with the other negative symptom domains in schizophrenia, and successfully remediating avolition results in global improvement in the entire constellation of negative symptoms. Avolition may therefore reflect the most critical treatment target within the negative symptom construct. Implications for targeted treatment development and clinical trial design are discussed.

EPA guidance on assessment of negative symptoms in schizophrenia

Background

During the last decades, a renewed interest for negative symptoms (NS) was brought about by the increased awareness that they interfere severely with real-life functioning, particularly when they are primary and persistent.

Methods

In this guidance paper, we provide a systematic review of the evidence and elaborate several recommendations for the conceptualization and assessment of NS in clinical trials and practice.

Results

Expert consensus and systematic reviews have provided guidance for the optimal assessment of primary and persistent negative symptoms; second-generation rating scales, which provide a better assessment of the experiential domains, are available; however, NS are still poorly assessed both in research and clinical settings.

This European Psychiatric Association (EPA) guidance recommends the use of persistent negative symptoms (PNS) construct in the context of clinical trials and highlights the need for further efforts to make the definition of PNS consistent across studies in order to exclude as much as possible secondary negative symptoms. We also encourage clinicians to use second-generation scales, at least to complement first-generation ones.

The EPA guidance further recommends the evidence-based exclusion of several items included in first-generation scales from any NS summary or factor score to improve NS measurement in research and clinical settings. Self-rated instruments are suggested to further complement observer-rated scales in NS assessment.

Several recommendations are provided for the identification of secondary negative symptoms in clinical settings.

Conclusions

The dissemination of this guidance paper may promote the development of national guidelines on negative symptom assessment and ultimately improve the care of people with schizophrenia.

Idiographic analyses of motivation and related processes in participants with schizophrenia following a therapeutic intervention for negative symptoms

BACKGROUND

Motivational negative symptoms hinder quality of life and daily functioning of individuals with schizophrenia spectrum disorders. A recently developed intervention, Switch, has shown promising effects on negative symptoms and functional outcomes. Switch targets multiple cognitive, emotional and behavioural processes associated with motivation and goal directed behaviours. We aimed to investigate its effects on motivation and associated processes in a naturalistic setting, and to explore the dynamics between the processes.

METHODS

We used a single case approach (n = 3), with a pre-post and follow-up assessment design, which also included ambulatory assessments (experience sampling method, ESM; and step count). We computed autoregressive lag 1 models to evaluate the effects of the intervention on daily motivation levels and related processes, descriptive pie-charts, and vector autoregressive modelling to reveal the dynamics of the processes over time.

RESULTS

The intervention was beneficial for each participant according to traditional evaluations of motivational negative symptoms, apathy, daily functioning and quality of life. The effects on the ESM variables revealed distinct outcomes for each individual. The dynamics between the various processes differed between participants, and fluctuated within participants (when comparing baseline, intervention phase, and follow-up).

CONCLUSIONS

This study used an innovative approach to look at the effectiveness of an intervention. The intervention seems to lead to meaningful improvements in motivational negative symptoms and functional outcomes. The mechanisms of change need to be further investigated.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT04325100 . Registered 27 March 27, 2020 -retrospectively registered.

REPORTING

Guidelines from the Transparent Reporting of Evaluations with Non-randomized Designs (TREND) statement were followed.

The shared genetic architecture of schizophrenia, bipolar disorder and lifespan

Psychiatric disorders such as Schizophrenia (SCZ) and Bipolar Disorder (BD) represent an evolutionary paradox, as they exhibit strong negative effects on fitness, such as decreased fecundity and early mortality, yet they persist at a worldwide prevalence of approximately 1%. Molecular mechanisms affecting lifespan, which may be widely common among complex diseases with fitness effects, can be studied by the integrated analysis of data from genome-wide association studies (GWAS) of human longevity together with any disease of interest. Here, we report the first of such studies, focusing on the genetic overlap-pleiotropy-between two psychiatric disorders with shortened lifespan, SCZ and BD, and human parental lifespan (PLS) as a surrogate of life expectancy. Our results are twofold: first, we demonstrate extensive polygenic overlap between SCZ and PLS and to a lesser extent between BD and PLS. Second, we identified novel loci shared between PLS and SCZ (n = 39), and BD (n = 8). Whereas most of the identified SCZ (66%) and BD (62%) pleiotropic risk alleles were associated with reduced lifespan, we also detected some antagonistic protective alleles associated to shorter lifespans. In fact, top-associated SNPs with SCZ seems to explain longevity variance explained (LVE) better than many other life-threatening diseases, including Type 2 diabetes and most cancers, probably due to a high overlap with smoking-related pathways. Overall, our study provides evidence of a genetic burden driven through premature mortality among people with SCZ, which can have profound implications for understanding, and potentially treating, the mortality gap associated with this psychiatric disorder.

A Meta-Analysis of Neuropsychological Effort Test Performance in Psychotic Disorders

Psychotic disorders are characterized by a generalized neurocognitive deficit (i.e., performance 1.5 SD below controls across neuropsychological domains with no specific profile of differential deficits). A motivational account of the generalized neurocognitive deficit has been proposed, which attributes poor neuropsychological testing performance to low effort. However, findings are inconsistent regarding effort test failure rate in individuals with psychotic disorders across studies (0-72%), and moderators are unclear, making it difficult to know whether the motivational explanation is viable. To address these issues, a meta-analysis was performed on data from 2205 individuals with psychotic disorders across 19 studies with 24 independent effects. Effort failure rate was examined along with moderators of effort test type, forensic status, IQ, positive symptoms, negative symptoms, diagnosis, age, gender, education, and antipsychotic use. The pooled weighted effort test failure rate was 18% across studies and there was a moderate pooled association between effort failure rate and global neurocognitive performance (r = .57). IQ and education significantly moderated failure rate. Collectively, these findings suggest that a nontrivial proportion of individuals with a psychotic disorder fail effort testing, and failure rate is associated with global neuropsychological impairment. However, given that effort tests are not immune to the effects of IQ in psychotic disorders, these results cannot attest to the viability of the motivational account of the generalized neurocognitive deficit. Furthermore, the significant moderating effect of IQ and education on effort test performance suggests that effort tests have questionable validity in this population and should be interpreted with caution.

Network Analysis Indicates That Avolition Is the Most Central Domain for the Successful Treatment of Negative Symptoms: Evidence From the Roluperidone Randomized Clinical Trial

A recent conceptual development in schizophrenia is to view its manifestations as interactive networks rather than individual symptoms. Negative symptoms, which are associated with poor functional outcome and reduced rates of recovery, represent a critical need in schizophrenia therapeutics. MIN101 (roluperidone), a compound in development, demonstrated efficacy in the treatment of negative symptoms in schizophrenia. However, it is unclear how the drug achieved its effect from a network perspective. The current study evaluated the efficacy of roluperidone from a network perspective. In this randomized clinical trial, participants with schizophrenia and moderate to severe negative symptoms were randomly assigned to roluperidone 32 mg (n = 78), 64 mg (n = 83), or placebo (N = 83). Macroscopic network properties were evaluated to determine whether roluperidone altered the overall density of the interconnections among symptoms. Microscopic properties were evaluated to examine which individual symptoms were most influential (ie, interconnected) on other symptoms in the network and are responsible for successful treatment effects. Participants receiving roluperidone did not differ from those randomized to placebo on macroscopic properties. However, microscopic properties (degree and closeness centrality) indicated that avolition was highly central in patients receiving placebo and that roluperidone reduced this level of centrality. These findings suggest that decoupling the influence of motivational processes from other negative symptom domains is essential for producing global improvements. The search for pathophysiological mechanisms and targeted treatment development should be focused on avolition, with the expectation of improvement in the entire constellation of negative symptoms if avolition is effectively treated.

Emerging 5-HT receptor antagonists for the treatment of Schizophrenia

INTRODUCTION

While antipsychotics have been generally successful in treating psychosis in schizophrenia, there is a major treatment gap for negative symptoms and cognitive deficits. Given that these aspects of the disease contribute to poor functional outcomes independently of positive symptoms, treatments would have profound implications for quality of life. The 5-HT_2A- receptor has been considered a potential target for interventions aimed at negative and cognitive symptoms and multiple antagonists and inverse agonists of this receptor have been tested.

AREAS COVERED

Ritanserin and volinanserin, are historically important compounds in this area, while pimavanserin, roluperidone, and lumateperone are either newly approved, in late stages of development, or currently being tested for efficacy in schizophrenia-related features. The focus will be on their efficacy in the treatment of negative symptoms, with a limited secondary discussion of cognition.

EXPERT OPINION

In addition to their efficacy in treating negative symptoms and cognition, these compounds may also have a role in modulating antipsychotic-induced dopamine super-sensitivity and preventing relapse. They may also show efficacy in treating patients with milder symptoms such as patients with schizotypal personality disorder and attenuated psychosis syndrome. Their utility may also expand outside the spectrum of schizophrenia to encompass Parkinson's Disease psychosis, major depression, bipolar depression, and dementia-associated apathy.

The brief negative symptom scale in translation: A review of psychometric properties and beyond

Negative symptoms are a core feature of schizophrenia and associated with social and occupational impairment. To encourage treatment development and address the limitations of existing rating instruments in this area across culture, the Brief Negative Symptoms Scale (BNSS) was developed. The authors reviewed studies published since the BNSS was published in 2010 that examined the psychometric properties of the instrument in translation and compared for consistency, psychometric performance and related features. Eleven published cross-cultural validation studies demonstrated the translated versions of the BNSS have strong psychometric properties, similar to the original English version. The internal consistency ranged from 0.88 to 0.98 and the inter-rater reliability ranged from 0.81 to 0.98 for the total score. The BNSS exhibited good convergent validity with existing measures of similar constructs and function, and good discriminant validity relative to other constructs. Recent research also reported that the BNSS is sensitive to drug effects, with effect sizes comparable to established scales. The results of confirmatory factor analyses revealed that the 5-factor structure of negative symptoms in schizophrenia (blunted affect, anhedonia, avolition, asociality, and alogia) crosses cultures. This psychometric evidence suggests that the BNSS is a valid and reliable instrument for assessing pathological mechanism underlying the negative symptoms of schizophrenia across cultures and can be a useful instrument in global clinical trials.

Effects of Roluperidone (MIN-101) on two dimensions of the negative symptoms factor score: Reduced emotional experience and reduced emotional expression

BACKGROUND

Recent research has suggested that negative symptoms (NS) can be considered in terms of two different dimensions: reduced expression (expressive deficit) and reduced experience (experiential deficit). Roluperidone, a compound with high affinities for 5 HT2A and sigma2 receptors, has previously shown superiority over placebo on improving NS in a prospective study in patients with schizophrenia. The objective here is to explore the effect of roluperidone compared to placebo, on the 2 domains of the Negative Symptoms.

METHODS

This was a multi-national Phase 2b trial that enrolled 244 symptomatically stable patients with schizophrenia who had baseline scores ≥20 on the NS subscale of the PANSS. Patients were randomized to daily monotherapy with roluperidone 32 mg, roluperidone 64 mg, or placebo in a 1:1:1 ratio. All enrolled patients were Caucasian, and 137 (56%) were male. The 3 treatment groups were balanced on all demographic and illness-related baseline characteristics.

RESULTS

Both doses of roluperidone were superior to placebo on both domains: Reduced Experience (p ≤ .006 for the 32 mg; p ≤ .001 for the 64 mg) with persistent superiority from Week 2 for the 64 mg dose and Week 8 for the 32 mg dose; Reduced Expression (p ≤ .003 for 32 mg; p ≤ .001 for 64 mg) with similar persistence.

IMPLICATIONS

Both doses of roluperidone previously improved PANSS negative symptoms in general and demonstrated tolerability in stable schizophrenia patients. The post hoc analysis reported here found the drug to work on both the reduced emotional experience and reduced emotional expression sub-scales empirically derived from the PANSS.

Validation of the Danish version of the brief negative symptom scale

Objective: The Brief Negative Symptom Scale (BNSS) is an instrument for evaluating negative symptoms (NS) in schizophrenia based on the 2005 consensus statement by the National Institute of Mental Health. This study examines the validity and reliability of the Danish version of BNSS. Materials and methods: Acutely and chronically affected patients with schizophrenia or schizoaffective disorder were assessed with BNSS along with other psychopathological scales and clinical measures. Convergent and discriminant validity of BNSS was evaluated by its relationships with these assessments. Inter-rater agreement was estimated by the intraclass correlation coefficient (ICC). Results: Forty-nine subjects were included; the mean age was 33.1 (±10.8) years and 32 (65%) were males. BNSS correlated strongly with traditional assessment tools for NS and poorly with measures of depressive and extrapyramidal symptoms, except for Parkinsonism. Moreover, BNSS correlated well with the assessment of positive symptoms. The ICC of BNSS was 0.95 (n = 19, 95% CI: 0.88-0.98). Conclusions: Overall, BNSS holds appropriate psychometric properties in terms of reliability and validity. However, discriminant validity was compromised by correlations with positive symptoms and Parkinsonism. The former originates presumably from NS secondary to positive symptoms since the sample included acutely psychotic patients, and the latter from overlapping rating criteria regarding facial expressivity impairment.

Pilot Validation Study of the Japanese Translation of the Brief Negative Symptoms Scale (BNSS)

PURPOSE

The brief negative symptoms scale (BNSS) is a concise instrument used to assess negative symptoms of subjects with schizophrenia covering five domains of negative symptoms and is suitable for use in clinical, experimental, and epidemiological settings. The original and translated version of BNSS has thus far been shown to have adequate psychometric properties. This study aimed to examine internal consistency, inter-rater and test-retest reliability, discriminant and convergent validity, and factor structure of the Japanese version of BNSS.

PATIENTS AND METHODS

The assessment was performed by 11 raters using interview videos of nine subjects. Reliability was calculated with Cronbach's alpha for internal consistency and intra class correlation coefficient (ICC) for inter-rater reliability. Pearson's correlation coefficients were calculated to estimate the test-retest reliability. In addition to BNSS, Scale for assessment of negative symptoms (SANS) and scale for assessment of positive symptoms (SAPS) was obtained to assess the convergent and discriminant validity. Factor structure was assessed using principle factor analysis.

RESULTS

The Japanese BNSS showed excellent internal consistency (Cronbach's alpha=0.95), inter-rater reliability (intra class correlation coefficient=0.97), and test-retest reliability (r=0.94, p<0.001). The convergent validity shown by correlation with SANS total score (r=0.87, p<0.001) and discriminant validity shown by correlation with SAPS total score (r=0.17, p=-0.68) were also good. Principal factor analysis revealed a two-factor structure of BNSS, although the loading of each item differed from that in the literature.

CONCLUSION

Our pilot study demonstrated that Japanese BNSS had good psychometric properties which were achieved with relatively brief training. Further studies with more subjects and raters with various backgrounds recruited from multiple sites are warranted.