Current developments and challenges in the assessment of negative symptoms

Clinical Assessment Interview for Negative Symptoms (CAINS): A Systematic Review of Measurement Properties

BACKGROUND AND HYPOTHESIS

Negative symptoms are very important for the overall loss of functioning observed in patients with schizophrenia. There is a need for valid tools to assess these symptoms.

STUDY DESIGN

We used the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) systematic review guideline to evaluate the quality of the clinical assessment interview for negative symptoms (CAINS) as a clinician-rated outcome measurement (ClinROM).

STUDY RESULTS

The search strategy resulted in the retrieval of 13 articles, 11 of which were included in this evaluation. In terms of risk of bias, most articles reported on measures of internal consistency and construct validity, which were overall of good quality. Structural validity, reliability, measurement error, and cross-cultural validity were reported with less than optimum quality. There was a risk of bias in ClinROM development. According to the updated criteria of good measurement properties, structural validity, internal consistency, and reliability showed good results. In contrast, hypothesis testing was somewhat poorer. Results for cross-cultural validity were indeterminate. According to the updated GRADE approach from the COSMIN group the scale received a moderate grade.

CONCLUSIONS

The COSMIN standard allows a judgment of the CAINS as an instrument with the potential to be recommended for use, but which requires further research to assess its quality, in particular in the domains of content validity, internal consistency, and cross-cultural validity.

Association of serum interleukin-6 with negative symptoms in stable early-onset schizophrenia

BACKGROUND

Accumulating evidence suggests that the inflammatory cytokine interleukin-6 (IL-6) contributes to the pathophysiology of psychiatric disorders. However, there was no study concerning the relationship between IL-6 concentrations and clinical features in the chronic phase of early-onset schizophrenia (EOS).

AIM

To investigate the relationship between serum IL-6 concentration and the clinical features of EOS.

METHODS

We measured serum IL-6 Levels from 74 patients with chronic schizophrenia, including 33 with age at onset < 21 years (EOS group) and 41 with onset ≥ 21 years in [adult-onset schizophrenia (AOS) group], and from 41 healthy controls. Symptom severities were evaluated using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Serum IL-6 concentrations were higher in both EOS and AOS groups than healthy controls (F = 22.32, P < 0.01), but did not differ significantly between EOS and AOS groups (P > 0.05) after controlling for age, body mass index, and other covariates. Negative symptom scores were higher in the EOS group than the AOS group (F = 6.199, P = 0.015). Serum IL-6 concentrations in the EOS group were negatively correlated with both total PANSS-negative symptom score (r = -0.389, P = 0.032) and avolition/asociality subscore (r = -0.387, P = 0.026).

CONCLUSION

Patients with EOS may have more severe negative symptoms than those with adult-onset schizophrenia during the chronic phase of the illness. IL-6 signaling may regulate negative symptoms and its avolition/asociality subsymptoms among the early-onset chronic schizophrenic patients.

Effect of applying nursing-based cognitive defusion techniques on mindful awareness, cognitive fusion, and believability of delusions among clients with schizophrenia: a randomized control trial

Background

Applying cognitive defusion techniques to enduring psychotic symptoms, such as delusions, presents both a challenge and a promising opportunity for psychiatric nurses to manage delusions among schizophrenia clients.

Objective

This study aimed to examine the impact of cognitive defusion techniques on psychological flexibility, mindful awareness, cognitive fusion, and the believability of delusions in schizophrenia clients.

Methodology

This study used a single-blind, parallel-arm Randomized Controlled Trial design. Over five weeks, 70 clients with schizophrenia were randomized to either the cognitive defusion intervention group (n = 35) or the control group (n = 35).

Findings

The participants showed significant reductions in the believability of delusions, cognitive fusion, and psychological inflexibility immediately after the intervention and at follow-up. Notable enhancements were observed in cognitive defusion and mindfulness awareness abilities.

Conclusion

Cognitive defusion techniques positively affect schizophrenia clients who struggle with persistent delusional beliefs. This underscores the importance of further investigating this approach to decrease the intensity of delusions as part of a comprehensive therapeutic intervention. Psychiatric nurses must receive training in "cognitive defusion skills" to aid schizophrenia clients in becoming more aware of their emotions and modifying their coping strategies for delusional beliefs. On August 3, 2023, the research was retrospectively registered under the reference number NCT05759091 as a randomized clinical trial.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT05759091, identifier NCT05759091.

Turning the Spotlight on Apathy: Identification and Treatment in Schizophrenia Spectrum Disorders

Among negative symptoms, apathy is central to the impairments in real-life functioning in schizophrenia spectrum disorders (SSD). Thus, optimizing treatment for apathy appears key to improve outcomes. In treatment research, however, negative symptoms are typically studied as a unifactorial construct. We, therefore, aim to shed necessary light on the status of apathy identification and treatment in SSD.

Negative Symptom Inventory-Self-Report (NSI-SR): Initial development and validation

Negative symptoms (i.e., anhedonia, avolition, asociality, blunted affect, alogia) are frequently observed in the schizophrenia-spectrum (SZ) and associated with functional disability. While semi-structured interviews of negative symptoms represent a gold-standard approach, they require specialized training and may be vulnerable to rater biases. Thus, brief self-report questionnaires measuring negative symptoms may be useful. Existing negative symptom questionnaires demonstrate that this approach may be promising in schizophrenia, but no measure has been devised for use across stages of psychotic illness. The present study reports initial psychometric validation of the Negative Symptom Inventory-Self-Report (NSI-SR), the self-report counterpart of the Negative Symptom Inventory-Psychosis Risk clinical interview. The NSI-SR is a novel transphasic negative symptoms measure assessing the domains of anhedonia, avolition, and asociality. The NSI-SR and related measures were administered to two samples: 1) undergraduates (n = 335), 2) community participants, including: SZ (n = 32), clinical-high risk for psychosis (CHR, n = 25), and healthy controls matched to SZ (n = 31) and CHR (n = 30). The psychometrically trimmed 11-item NSI-SR showed good internal consistency and a three-factor solution reflecting avolition, asociality, and anhedonia. The NSI-SR demonstrated convergent validity via moderate to large correlations with clinician-rated negative symptoms and related constructs in both samples. Discriminant validity was supported by lower correlations with positive symptoms in both samples; however, correlations with positive symptoms were still significant. These initial psychometric findings suggest that the NSI-SR is a reliable and valid brief questionnaire capable of measuring negative symptoms across phases of psychotic illness.

Bridge centrality network structure of negative symptoms in people with schizophrenia

Negative symptoms are complex psychopathology. Although evidence generally supported the NIMH five consensus domains, research seldom examined measurement invariance of this model, and domain-specific correspondence across multiple scales. This study aimed to examine the interrelationship between negative symptom domains captured by different rating scales, and to examine the domain-specific correspondence across multiple scales. We administered the Brief Negative Symptom Scale (BNSS), the Self-evaluation of Negative Symptoms (SNS), and the Scale for Assessment of Negative Symptoms (SANS) to 204 individuals with schizophrenia. We used network analysis to examine the interrelationship between negative symptom domains. Besides regularized partial correlation network, we estimated bridge centrality indices to investigate domain-specific correspondence, while taking each scale as an independent community. The regularized partial correlation network showed that the SNS nodes clustered together, whereas the SANS and the BNSS nodes intermingled together. The SANS attention domain lied at the periphery of the network according to the Fruchterman-Reingold algorithm. The SANS anhedonia-asociality (strength = 1.48; EI = 1.48) and the SANS affective flattening (strength = 1.06; EI = 1.06) had the highest node strength and EI. Moreover, the five nodes of the BNSS bridged the nodes of the SANS and the SNS. BNSS blunted affect (strength = 0.76; EI = 0.76) and SANS anhedonia-asociality (strength = 0.76; EI = 0.74) showed the highest bridge strength and bridge EI. The BNSS captures negative symptoms and bridges the symptom domains measured by the SANS and the SNS. The three scales showed domain-specific correspondence.

Using dimensionality-reduction techniques to understand the organization of psychotic symptoms in persistent psychotic illness and first episode psychosis

Psychotic disorders are highly heterogeneous. Understanding relationships between symptoms will be relevant to their underlying pathophysiology. We apply dimensionality-reduction methods across two unique samples to characterize the patterns of symptom organization. We analyzed publicly-available data from 153 participants diagnosed with schizophrenia or schizoaffective disorder (fBIRN Data Repository and the Consortium for Neuropsychiatric Phenomics), as well as 636 first-episode psychosis (FEP) participants from the Prevention and Early Intervention Program for Psychosis (PEPP-Montreal). In all participants, the Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS) were collected. Multidimensional scaling (MDS) combined with cluster analysis was applied to SAPS and SANS scores across these two groups of participants. MDS revealed relationships between items of SAPS and SANS. Our application of cluster analysis to these results identified: 1 cluster of disorganization symptoms, 2 clusters of hallucinations/delusions, and 2 SANS clusters (asocial and apathy, speech and affect). Those reality distortion items which were furthest from auditory hallucinations had very weak to no relationship with hallucination severity. Despite being at an earlier stage of illness, symptoms in FEP presentations were similarly organized. While hallucinations and delusions commonly co-occur, we found that their specific themes and content sometimes travel together and sometimes do not. This has important implications, not only for treatment, but also for research-particularly efforts to understand the neurocomputational and pathophysiological mechanism underlying delusions and hallucinations.

Primary and secondary negative symptoms severity and the use of psychiatric care resources in schizophrenia spectrum disorders: A 3-year follow-up longitudinal retrospective study

Negative symptoms represent one of the core features of schizophrenia spectrum disorders (SSD), strongly correlated with low remission rates, poor real-world functioning, and worse quality of life. Despite the body of evidence attesting the role of negative symptoms in determining worse outcomes in SSD, few studies have directly investigated their impact on the use of psychiatric services and even fewer research have examined the differential impact between primary versus secondary negative symptoms. The present study aims to investigate whether SSD subjects with high levels of primary and of secondary negative symptoms at an index hospitalization show a different use of psychiatric services in the subsequent 3 years. A total of 429 subjects were included in the study. Results show that SSD patients with high levels of negative symptoms are characterized by an overall greater use of high-cost resources, with more admissions in the hospital acute care psychiatric ward and in high intensity residential inpatient services. Moreover, while primary negative symptoms appear to play a role in determining a greater use of psychiatric services, high levels of secondary negative symptoms are associated with an increased use of most psychiatric resources, especially of high-cost ones. In conclusion, negative symptoms have a relevant impact on the pattern of psychiatric resources utilization in SSD patients. While scientific research continues to look for effective treatments for primary negative symptoms, clinicians should pay particular attention to secondary negative symptoms, as these also have important consequences but may benefit from appropriate treatment.

Identifying and revealing different brain neural activities of cognitive subtypes in early course schizophrenia

Background

Cognitive subtypes of schizophrenia may exhibit different neurobiological characteristics. This study aimed to reveal the underlying neurobiological features between cognitive subtypes in the early course of schizophrenia (ECS). According to prior studies, we hypothesized to identify 2–4 distinct cognitive subtypes. We further hypothesized that the subtype with relatively poorer cognitive function might have lower brain spontaneous neural activity than the subtype with relatively better cognitive function.

Method

Cognitive function was assessed by the MATRICS Consensus Cognitive Battery (MCCB). Resting-state functional magnetic resonance imaging scanning was conducted for each individual. There were 155 ECS individuals and 97 healthy controls (HCs) included in the subsequent analysis. Latent profile analysis (LPA) was used to identify the cognitive subtypes in ECS individuals, and amplitude of low-frequency fluctuations (ALFFs) was used to measure brain spontaneous neural activity in ECS individuals and HCs.

Results

LPA identified two cognitive subtypes in ECS individuals, containing a severely impaired subtype (SI, n = 63) and a moderately impaired subtype (MI, n = 92). Compared to HCs, ECS individuals exhibited significantly increased ALFF in the left caudate and bilateral thalamus and decreased ALFF in the bilateral medial prefrontal cortex and bilateral posterior cingulate cortex/precuneus (PCC/PCu). In ECS cognitive subtypes, SI showed significantly higher ALFF in the left precentral gyrus (PreCG) and lower ALFF in the left PCC/PCu than MI. Furthermore, ALFFs of left PreCG were negatively correlated with several MCCB cognitive domains in ECS individuals, while ALFF of left PCC/PCu presented opposite correlations.

Conclusion

Our findings suggest that differences in the brain spontaneous neural activity of PreCG and PCC/PCu might be the potential neurobiological features of the cognitive subtypes in ECS, which may deepen our understanding of the role of PreCG and PCC/PCu in the pathogenesis of cognitive impairment in schizophrenia.

Awareness of illness moderates self-assessment of psychotic symptoms

OBJECTIVE

Self-reports or patient-reported outcome measures are seldom used in psychosis due to concerns about the ability of patients to accurately report their symptomatology, particularly in cases of low awareness of illness. The aim of this study was to assess the effect of insight on the accuracy of self-reported psychotic symptoms using a computerized adaptive testing tool (CAT-Psychosis).

METHODS

A secondary analysis of data drawn from the CAT-Psychosis development and validation study was performed. The Brief Psychiatric Rating Scale and the Scale of Unawareness of Mental Disorders were administered by clinicians. Patients completed the self-reported version of the CAT-Psychosis. Patients were median-split regarding their insight level to compare the correlation between the two psychosis severity measures. A subgroup sensitivity analysis was performed only on patients with schizophrenia spectrum disorders.

RESULTS

A total of 159 patients with a psychotic disorder who completed both CAT-Psychosis and Scale of Unawareness of Mental Disorders were included. For the whole sample, CAT-Psychosis scores showed convergent validity with Brief Psychiatric Rating Scale ratings (r = 0.517, 95% confidence interval = [0.392, 0.622], p < 0.001). Insight was found to moderate this correlation (β = -0.511, p = 0.005), yet agreement between both measures remained statistically significant for both high (r = 0.621, 95% confidence interval = [0.476, 0.733], p < 0.001) and low insight patients (r = 0.408, 95% confidence interval = [0.187, 0.589], p < 0.001), while psychosis severity was comparable between these groups (for Brief Psychiatric Rating Scale: U = 3057, z = -0.129, p = 0.897; disorganization: U = 2986.5, z = -0.274, p = 0.784 and for CAT-Psychosis: U = 2800.5, z = -1.022, p = 0.307). Subgroup of patients with schizophrenia spectrum disorders showed very similar results.

CONCLUSIONS

Insight moderates the correlation between self-reported and clinician-rated severity of psychosis, yet CAT-Psychosis remains valid in patients with both high and low awareness of illness.

Implicit cognitive effort monitoring impairments are associated with expressive negative symptoms in schizophrenia

Negative symptoms are a strong predictor of functional impairment in schizophrenia (SZ). Unfortunately, mechanisms underlying negative symptoms are poorly understood and available treatments are minimally effective. The current study evaluated the novel hypothesis that negative symptoms are associated with an implicit cognitive effort monitoring impairment that manifests during tasks requiring sustained allocation of cognitive control. Outpatients with SZ (n = 33) and healthy controls (CN; n = 29) completed an adapted Demand Selection Task (DST) in which subjects made choices between pairs of cognitive tasks that were implicitly and then explicitly made discrepant in effort demands. The SZ group demonstrated a reduced probability of avoiding the high effort cognitive task in the implicit choice condition but were able to become effort avoidant when the demands of the task were made explicit. Implicit cognitive effort monitoring deficits were associated with greater severity of the expressivity dimension of negative symptoms, but not the motivation and pleasure dimension. The association between diminished expressivity and implicit cognitive effort monitoring deficits is interpreted in light of a novel cognitive resource depletion theory, whereby individuals with SZ may become less expressive due to difficulty implicitly monitoring ongoing cognitive effort exertion and dynamically adjusting effort expenditure as task demands fluctuate.

Validation of the Turkish version of the self-evaluation of negative symptoms scale (SNS)

OBJECTIVES

The Self-Evaluation of Negative Symptoms Scale (SNS) is a self-report scale that evaluates a patient's subjective experience on all five domains of the negative symptoms. This study aimed to present the adaptation and validation study of the Turkish version of SNS(SNS-TR).

METHODS

Seventy-five patients and 50 controls were recruited for this study. After the approval of the translation, participants were asked to fill out SNS-TR by themselves. They were interviewed with the Brief Negative Symptoms Scale (BNSS), Positive and Negative Syndrome Scale (PANSS), and Calgary Depression Scale for Schizophrenia (CDSS).

RESULTS

SNS-TR showed good internal consistency in the reliability analysis with Cronbach's alpha= 0.873. Subscale-total score correlation coefficients were significant (p < 0.01). In the validity analyses, the total and subscale scores of SNS-TR showed positive correlations with the total and subscales of BNSS, with only one exception of BNSS lack of distress subscales. The total score of SNS-TR demonstrated a significant correlation with PANSS-total, PANSS-negative subscale, PANSS-general subscale, and CDSS scores. Confirmatory factor analysis showed acceptable values for the five-factor structure, similar to the original version.

CONCLUSION

To conclude, our study indicates that SNS-TR is an easily applicable self-evaluation tool with good psychometric properties for assessing negative symptoms. KEY POINTSSNS is a novel and easily applicable self-report scale for examining negative symptoms in schizophrenia patients, allowing them to evaluate their subjective experience on all five domains of the negative symptoms.It shows good internal consistency (α= 0.873) which is similar to the original version (α = 0.867).Confirmatory factor analysis scores were found in acceptable ranges and SNS-TR confirm the five-factor structure.Using this scale in clinical practice would empower both the physician's examinations and patient participation through treatment and follow-up course.

Associations between aerobic fitness, negative symptoms, cognitive deficits and brain structure in schizophrenia-a cross-sectional study

Negative symptoms and cognitive deficits are common in individuals with schizophrenia, greatly affect their outcome, and have been associated with alterations in cerebral gray and white matter volume (GMV, WMV). In the last decade, aerobic endurance training has emerged as a promising intervention to alleviate these symptoms and improved aerobic fitness has been suggested as a key moderator variable. In the present study, we investigated, whether aerobic fitness is associated with fewer cognitive deficits and negative symptoms and with GMVs and WMVs in individuals with schizophrenia in a cross-sectional design. In the largest study to date on the implications of fitness in individuals with schizophrenia, 111 participants at two centers underwent assessments of negative symptoms, cognitive functioning, and aerobic fitness and 69 underwent additional structural magnetic resonance imaging. Multilevel Bayesian partial correlations were computed to quantify relationships between the variables of interest. The main finding was a positive association of aerobic fitness with right hippocampal GMV and WMVs in parahippocampal and several cerebellar regions. We found limited evidence for an association of aerobic fitness with cognitive functioning and negative symptoms. In summary, our results strengthen the notion that aerobic fitness and hippocampal plasticity are interrelated which holds implications for the design of exercise interventions in individuals with schizophrenia.

Longitudinal invariance of the positive and negative syndrome scale negative dimension in antipsychotic naïve first-episode schizophrenia

AIM

Construct stability over time is required for reliable inference, but evidence regarding the longitudinal invariance of negative symptoms is still limited. Thus, we examined the longitudinal invariance of the negative dimension using the positive and negative syndrome scale (PANSS) in an antipsychotic-naïve first-episode schizophrenia sample at baseline and after 10 weeks.

METHODS

Our study was conducted at a specialized early intervention service. PANSS ratings were analysed for 138 patients, and two different models were specified and tested: a unidimensional and a two-correlated factor solution.

RESULTS

The unidimensional model fulfilled criteria for longitudinal invariance, whilst the two-correlated did not.

CONCLUSION

Our study provides support for the PANSS negative unidimensional model use to evaluate negative symptoms' longitudinal change following first-episode schizophrenia.

From Memories of Past Experiences to Present Motivation? A Meta-analysis on the Association Between Episodic Memory and Negative Symptoms in People With Psychosis

Based on findings from cognitive science, it has been theorized that the reductions in motivation and goal-directed behavior in people with psychosis could stem from impaired episodic memory. In the current meta-analysis, we investigated this putative functional link between episodic memory deficits and negative symptoms. We hypothesized that episodic memory deficits in psychosis would be related to negative symptoms in general but would be more strongly related to amotivation than to reduced expressivity. We included 103 eligible studies (13,622 participants) in the analyses. Results revealed significant, moderate negative associations of episodic memory with negative symptoms in general (k = 103; r = -.23; z = -13.40; P ≤ .001; 95% CI [-.26; -.20]), with amotivation (k = 16; r = -.18; z = -6.6; P ≤ .001; 95% CI [-.23; -.13]) and with reduced expressivity (k = 15; r = -.18; z = -3.30; P ≤.001; 95% CI[-.29; -.07]). These associations were not moderated by sociodemographic characteristics, positive symptoms, depression, antipsychotic medication or type of negative symptom scale. Although these findings provide sound evidence for the association between episodic memory deficits and amotivation, the rather small magnitude and the unspecific pattern of this relationship also indicate that episodic memory deficits are unlikely to be the only factor relevant to amotivation. This implicates that future research should investigate episodic memory in conjunction with other factors that could account for the association of episodic memory deficits and amotivation in psychosis.

Compassion-based approaches: a systematic review of their effectiveness and acceptability in schizophrenia spectrum disorders

The purpose of this systematic literature review is to provide an exhaustive summary of current research to explore the prospects of compassion-based approaches in treating persons with Schizophrenia Spectrum Disorders (SSD). Thereby, studies investigating the relationship between clinical parameters and self-compassion in SSD, as well as the acceptability, feasibility, and effects of compassion-based approaches for individuals with SSD were considered. The review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Eight studies were included for qualitative synthesis. The results indicate an important role of self-compassion for several clinical parameters, including negative associations to positive symptoms, negative symptoms, cognitive disorganization, and emotional distress. All studies reported good acceptability and feasibility. Regarding the clinical effectiveness of compassion-based approaches, a variety of clinical benefits, such as improvements of mood, affect regulation, positive symptoms, negative symptoms, cognitive disorganization, and variables relating to psychological recovery were found in individuals with SSD. It is concluded that compassion-based approaches are a promising form of intervention in the treatment of SSD. However, further research, especially randomized controlled trials, in this field is needed to understand the full potential of compassion-based approaches for individuals with SSD.

Psychometric properties of the BIRT Motivation Questionnaire (BMQ), a self-measure of avolition in individuals with schizophrenia

AIMS

Avolition defined as a lack of interest or engagement in goal-directed behavior plays a key role in everyday functioning in schizophrenia and is considered as one of the main contributors to the burden of disease. The aim of this study was to 1) validate the self-report BIRT Motivation Questionnaire (BMQ-S) seldom used before in schizophrenia 2) examine the degree of agreement between the BMQ-S and its informant-report version 3) to assess its ability to predict real-world outcome at 12 month follow-up.

METHODS

One hundred and twenty-two (51.9% inpatients) adults with a diagnosis of schizophrenia were included. Exploratory Factor analysis was performed on the BMQ-S to identify the underlying structure. Real life functioning was measured with the Global Assessment of Functioning scale (GAF). Convergent validity was assessed with the Scale for Assessment of Negative Symptom (SANS) and the Lille Apathy Rating Scale (LARS).

RESULTS

The main psychometric properties of the BMQ-S (internal consistency, test-retest reliability) were satisfactory. Exploratory factorial analysis revealed a 4-factor model which explained 76% of the overall variance. The BMQ-S correlated significantly with the LARS and the SANS avolition subscore suggesting adequate convergent validity. The correlation between the BMQ-S and the clinician-report version was 0.48. The global score and in particular the Initiation/disorganisation dimension was a significant predictor of global functioning at 12-months even when adjusted for age, chlorpromazine intake and depression.

CONCLUSION

Our findings indicate that the BMQ-S has satisfactory psychometric properties and that schizophrenia patients can reliably assess their lack of motivation. Self-evaluation of avolition should be considered in the overall prediction of real-world functioning in schizophrenia.

Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

INTRODUCTION

Negative symptoms can be grouped into five domains: apathy/avolition, anhedonia, asociality, alogia, and affective flattening. There are few validate self-rated measures that assess these five dimensions. Therefore, this study aimed to validate the Self-Evaluation of Negative Symptoms (SNS) in Spanish patients with schizophrenia.

MATERIAL AND METHODS

Cross-sectional, validation study in 104 outpatients with schizophrenia evaluated using the Spanish version of the following scales: Clinical Assessment Interview for Negative Symptoms (CAINS), Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale for Schizophrenia (CGI-SCH), Personal and Social Performance (PSP), Motivation and Pleasure Scale - Self-Report (MAP-SR), 36-item Short-Form Health Survey (SF-36) and the Self-Evaluation of Negative Symptoms (SNS).

RESULTS RELIABILITY

Internal consistency (Cronbach's alpha) was 0.915. Convergent validity: The Pearson correlation coefficient between MAP-SR and SNS Total scores was 0.660 (p<0.001). For PANSS-N, the correlation was 0.437 (p<0.005) and with the CAINS-Total was 0.478 (p<0.005). Divergent validity: The Pearson correlation coefficient between SNS and PSP was r=-0.372 (p≤0.001), and with SF-36 Physical and Mental Summary Component scores were r=-0.213 (p=0.066) and r=-0.144 (p=0.219), respectively. Discriminant validity: SNS Total scores were significantly statistically different according to the severity of the negative symptomatology rated by the CGI-SCH negative scale (p<0.001).

CONCLUSION

The SNS is a reliable and valid instrument to self-rate the five domains of negative symptoms in patients with schizophrenia and seems to be appropriate for use in everyday clinical practice as a complementary measure to the evaluation performed by the clinician.

Recognizing Psychosis in Autism Spectrum Disorder

There is strong evidence for the existence of a high comorbidity between autism and psychosis with percentages reaching up to 34. 8% and several significant implications for treatment and prognosis of these patients. However, the identification of comorbid psychosis in patients with Autism Spectrum Disorder represents a complex challenge from a psychopathological point of view, in particular in patients with greater deficits in verbal communication. Intercepting the onset of a psychotic breakdown in autism may be very difficult, both disorders in fact occur along a phenotypic continuum of clinical severity and in many cases, psychotic symptoms are present in an attenuated form. In this paper, we reviewed the available scientific literature about comorbidity between psychosis and autism, focusing our attention on four specific dimensions: delusions, hallucinations, negative symptoms, and clinical course. The aim of this paper is to provide clinical tools to identify these psychotic phenomena in autistic patients, even when they occur in their attenuated form.

A blinded validation of the Swedish version of the Clinical Assessment Interview for Negative Symptoms (CAINS)

PURPOSE

The Clinical Assessment Interview for Negative Symptoms (CAINS) was developed in order to advance the assessment of negative symptoms. The aim of this study was to validate the Swedish version of the CAINS.

MATERIALS AND METHODS

Thirty-four out-patients with a schizophrenia spectrum disorder were recruited. All patients were videotaped while interviewed with the CAINS and the Brief Psychiatric Rating Scale (BPRS). Another rater watched the video recordings in the reverse order, enabling a blinded design. The patients also filled in self-reported measures of depression, quality of life, and social and vocational functioning. We calculated inter-rater agreement and internal consistency for the CAINS. We also calculated validity measures by correlating the subscales Motivation and Pleasure (CAINS-MAP) and Expression (CAINS-EXP) to subscales of the BPRS.

RESULTS

The blinded inter-rater agreement for the CAINS total score was high (ICC = 0.92) but slightly lower for the expression subscale (ICC = 0.76). Cronbach's alpha was 0.84 for the total score. Convergent validity with the negative symptoms subscale of BPRS was different for the blinded and the unblinded data, with a CAINS-MAP correlation of 0.10 (p = 0.580) and a CAINS-EXP correlation of 0.48 (p = 0.004) in the blinded data. The unblinded data had a CAINS-MAP correlation of 0.38 (p = 0.026) and a CAINS-EXP correlation of 0.87 (p < 0.001). Self-rated measures of anhedonia correlated to CAINS-MAP with a coefficient of 0.68 (p < 0.001), while the CAINS-EXP only had a correlation of 0.16 (p = 0.366) to these measures.

CONCLUSION

The Swedish version of the CAINS displays adequate psychometric properties in line with earlier validation studies.

The Relationship Between Mindfulness, Depression, Anxiety, and Quality of Life in Individuals With Schizophrenia Spectrum Disorders

Background: Schizophrenia spectrum disorders (SSD) are frequently accompanied by comorbid depressive and anxiety symptoms, as well as impaired quality of life (QoL). A growing body of evidence has demonstrated the relevance of mindfulness for SSD in recent years. The study examined the association between mindfulness, depression, anxiety, and QoL. Materials and Methods: A total of 83 participants with SSD were recruited at the in- and outpatient psychiatric hospital care. Participants completed the Southampton Mindfulness Questionnaire, Comprehensive Inventory for Mindful Experiences, and Freiburger Mindfulness Inventory, the Depression, Anxiety, Stress Scale to assess depression and anxiety, and the WHO-QoL Questionnaire. Multiple regression analyses examined the relationship between mindfulness and QoL and the mediating role of depression and anxiety. Results: Mindfulness had a significant statistical positive effect on QoL domains physical health, psychological, and environmental QoL in patients with SSD. Depression was identified as a significant mediator of this relationship. Conclusion: This study provides novel insight into mindfulness' mechanisms and paves the way for a process-oriented approach to treat SSD. The results provide first evidence for the process-based value of mindfulness for SSD; future studies can focus on the role of mindfulness for central therapeutic processes of change by employing longitudinal designs.

Validation of the lithuanian version of the self-evaluation of negative symptoms scale (SNS)

PURPOSE

To validate the Lithuanian version of the Self-Evaluation Negative Symptoms Scale (Lith-SNS).

MATERIALS AND METHODS

A double translation from French to Lithuanian and back was performed. We included patients from in-patient and out-patient settings that had a diagnosis of paranoid schizophrenia according to ICD-10 criteria and were screened as free from acute psychotic symptoms using the Mini International Neuropsychiatric Interview (MINI). Participants were evaluated using the Brief Psychiatric Rating Scale (BRPS) and completed the Lith-SNS scale. We measured internal consistency, convergent validity, and discriminant validity of Lith - SNS comparing its scores with BPRS negative and positive symptom subscores.

RESULTS

A total of 67 participants were evaluated. Cronbach's alpha (α) for all 20 items of Lith-SNS (α = 0.82), and for the five subscores (α = 0.76) showed good internal consistency. Factor analysis showed a 2-factor solution which accounted for 70.12% of the variance with the first factor accounting for 53.3% and the second factor accounting for 16.8% of the variance. Lith-SNS total scores and all five subscores significantly correlated with BPRS negative symptoms subscores showing good convergent validity. There was a correlation between the Positive subscore of BPRS and the alogia subscore of Lith-SNS (r = 0.39, p = 0.001), but no correlations with other subscores or the total Lith-SNS score showing adequate discriminant validity.

CONCLUSIONS

Lithuanian version of SNS is a valuable tool to evaluate negative symptoms of schizophrenia with good internal consistency, convergent, and discriminant validity.

Latent structure of self-report negative symptoms in patients with schizophrenia: A preliminary study

INTRODUCTION

Negative symptoms are associated with poor outcomes and functioning. Latent structure of negative symptoms is important for identifying potential intervention targets for novel treatments. Self-report instruments have been developed to measure negative symptoms. Previous findings on latent structure of negative symptoms are inconsistently and mainly rely on clinician-rated instruments.

METHOD

We aimed to explore the latent structure of the Self-Evaluation of Negative Symptoms Scale (SNS) in 204 clinically-stable outpatients with schizophrenia. Confirmatory factor analysis (CFA) was used to compare the competing models (i.e., one-factor, two-factor and five-factor models), and estimated goodness-of-fit indexes. Other clinician-rated scales for psychopathology and medication side-effects were also collected.

RESULTS

The CFA found the five-factor model performing best, with a comparative fit index (CFI) of > 0.95, a Tucker Lewis Index (TLI) of > 0.95, and a root mean square error of approximation (RMSEA) of < 0.06. The robust chi-square difference test for the weighted least squares with mean and variance adjusted estimation (WLSMV) also indicated a significant better fit for the five-factor model.

DISCUSSION

Our preliminary findings support a five-factor latent structure of self-report negative symptoms in schizophrenia patients. Further research in this area should utilize multiple clinician-rated and self-report measures, and recruit large and homogeneous samples with schizophrenia.

Negative symptoms in schizophrenia: correlation with clinical and genetic factors

Aim: Explore the possible association between clinical factors and genetic variants of the dopamine pathways and negative symptoms. Materials & methods: Negative symptoms were assessed in 206 patients with schizophrenia using the Arabic version of the self-evaluation of negative symptoms scale and the Positive and Negative Syndrome Scale. Genotyping for COMT, DRD2, MTHFR and OPRM1 genes was performed. Results: Multivariable analysis showed that higher self-evaluation of negative symptoms scale scores were significantly associated with higher age, higher chlorpromazine-equivalent daily dose for typical antipsychotics and in married patients. Higher negative Positive and Negative Syndrome Scale scores were significantly associated with women and having the CT genotype for MTHFR c.677C>T (β = 4.25; p = 0.008) compared with CC patients. Conclusion: Understanding both clinical/genetic factors could help improve the treatment of patients.

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.

Exploring the Psychometric Properties and the Factor Structure of the Calgary Depression Scale for Schizophrenia Across the Schizotypy Continuum

This study evaluated the psychometric properties and factor structure of the Calgary Depression Scale for Schizophrenia (CDSS) across different levels of the schizotypy continuum. A combined sample of high-schizotypy, at-risk mental states, and patients with first-episode psychosis was assessed for depression and other clinical and functional outcomes. Additionally, experience sampling methodology was used to assess depressive and psychotic-like experiences in daily life. The CDSS exhibited solid internal consistency, validity, and discrimination between depressed and nondepressed participants. Confirmatory factor analyses and the associations of the resulting factors with clinical and functional measures supported a two-factor structure that included general depression and guilt factors. Furthermore, both factors of the CDSS were differentially related to positive and negative symptoms of psychosis in daily life. The CDSS appears to have two underlying psychopathological dimensions and to be a reliable and valid measure for assessing depression across the schizotypy continuum.

Primary and Secondary Negative Symptoms in Schizophrenia

The negative symptoms of schizophrenia include volitional (motivational) impairment manifesting as avolition, anhedonia, social withdrawal, and emotional disorders such as alogia and affective flattening. Negative symptoms worsen patients' quality of life and functioning. From the diagnostic point of view, it is important to differentiate between primary negative symptoms, which are regarded as an integral dimension of schizophrenia, and secondary negative symptoms occurring as a result of positive symptoms, comorbid depression, side effects of antipsychotics, substance abuse, or social isolation. If secondary negative symptoms overlap with primary negative symptoms, it can create a false clinical impression of worsening deficit symptoms and disease progression, which leads to the choice of incorrect therapeutic strategy with excessive dopamine blocker loading. Different longitudinal trajectories of primary and secondary negative symptoms in different schizophrenia stages are proposed as an important additional discriminating factor. This review and position paper focuses primarily on clinical aspects of negative symptoms in schizophrenia, their definition, phenomenology, factor structure, and classification. It covers the historical and modern concepts of the paradigm of positive and negative symptoms in schizophrenia, as well as a detailed comparison of the assessment tools and psychometric tests used for the evaluation of negative symptoms.

A cognitive model of diminished expression in schizophrenia: The interface of metacognition, cognitive symptoms and language disturbances

The resistance of negative symptoms to pharmacologic treatment has spurred interest in understanding the psychological factors that contribute to their formation and persistence. However, little is understood about the psychological processes that reinforce and sustain the negative symptoms domain of diminished expression. Prior research has shown that higher levels of diminished expression relate to deficits in metacognitive capacity. We propose a more complex model in which diminished expression occurs when impairments in metacognitive self-reflectivity, alterations in higher-order language structure, and cognitive symptoms interact and thus interfere with persons' ability to understand and express emotions in ways others can recognize. Individuals with schizophrenia-spectrum disorders (N = 201) provided personal narratives detailing their life story and reflections about their mental illness. Self-reflectivity was measured with the Metacognition Assessment Scale-Abbreviated, and situation models were extracted from participants' personal narratives via Coh-Metrix 3.0, an automated program that calculates language indices. Diminished expression and cognitive symptoms were measured with the Positive and Negative Syndrome Scale. Structural equation models (SEM) examined whether self-reflectivity mediated the impact of cognitive symptoms and situation models on diminished expression. Results of the SEM revealed that self-reflectivity partially mediated the impact of situation models on diminished expression (β = -.073, p = .008, ±95% CI [-0.126, -0.019]). and fully mediated the influence of cognitive symptoms in diminished expression (β = 0.099, p = .001, ±95% CI [0.038, 0.160]). In conclusion, results suggest that self-reflectivity, linguistic cohesion, and cognitive symptoms may be useful targets for intervention in efforts to treat diminished expression in psychosis.

The psychometric properties of the Self-Evaluation of Negative Symptoms Scale (SNS) in treatment-resistant schizophrenia (TRS)

BACKGROUND

Clinician-administered measures of negative symptoms may not capture patients' subjective experiences. The Self-Evaluation of Negative Symptoms (SNS) has shown good psychometric properties when used in outpatients with higher-level functioning schizophrenia. We aimed to evaluate the psychometric properties of the SNS in low functioning participants with treatment-resistant schizophrenia (TRS).

METHODS

Participants were assessed using the following measures at two time-points; time-point 1: SNS, Wide Range Achievement Test, 4th Edition Reading Subtest (WRAT-4), and Brief Assessment of Cognition in Schizophrenia (BACS). Time-point 2 (within a week of time-point 1): SNS, Negative Symptom Assessment 16 items (NSA-16), Scale to Assess Unawareness in Mental Disorder-Abbreviated (SUMD-A), Clinical Global Impression Severity Scale (CGI-S), Simpson Angus Scale (SAS), Calgary Depression Scale for Schizophrenia (CDSS), and the Patient Feasibility Questionnaire.

RESULTS

Fifty participants with TRS were enrolled, a mean age of 43.8 years (SD = 11.19, min = 25, max = 64), a mean IQ of 80.62 (SD = 17.12, min = 65, max = 110), and a mean BACS Composite T-Score of 14.08 (SD = 17.16, min = -27, max = 49). Participants responded to SNS prompts with moderate consistency across two time-points. There were no significant correlations between the SNS and the NSA-16 Global Symptom score (Pearson r = 0.207, p = .150, Spearman r = 0.101, p = .483), NSA-16 Global Functioning score (Pearson r = 0.209, p = .145, Spearman r = 0.126, p = .384), nor the NSA-16 total score (Pearson r = 0.149, p = .302, Spearman r = 0.116, p = .421). However, when participants were stratified by BACS Composite T-score, there was a significant positive correlation between the SNS total and the NSA-16 Global Functioning score (Pearson r = 0.500, p = .048, Spearman r = 0.546, p = .029) among participants who demonstrated higher cognitive functioning.

CONCLUSION

Participants with TRS and low functioning were able to respond to questions on the SNS regarding their subjective assessment of negative symptoms. However, self-reported and clinician-rated negative symptoms were not equivalent, except in a subgroup with higher cognitive functioning. This discrepant self-reporting appeared to relate to their low levels of insight and cognitive impairments.

Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

INTRODUCTION

Negative symptoms can be grouped into five domains: apathy/avolition, anhedonia, asociality, alogia, and affective flattening. There are few validate self-rated measures that assess these five dimensions. Therefore, this study aimed to validate the Self-Evaluation of Negative Symptoms (SNS) in Spanish patients with schizophrenia.

MATERIAL AND METHODS

Cross-sectional, validation study in 104 outpatients with schizophrenia evaluated using the Spanish version of the following scales: Clinical Assessment Interview for Negative Symptoms (CAINS), Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale for Schizophrenia (CGI-SCH), Personal and Social Performance (PSP), Motivation and Pleasure Scale - Self-Report (MAP-SR), 36-item Short-Form Health Survey (SF-36) and the Self-Evaluation of Negative Symptoms (SNS).

RESULTS RELIABILITY

Internal consistency (Cronbach's alpha) was 0.915. Convergent validity: The Pearson correlation coefficient between MAP-SR and SNS Total scores was 0.660 (p<0.001). For PANSS-N, the correlation was 0.437 (p<0.005) and with the CAINS-Total was 0.478 (p<0.005). Divergent validity: The Pearson correlation coefficient between SNS and PSP was r=-0.372 (p≤0.001), and with SF-36 Physical and Mental Summary Component scores were r=-0.213 (p=0.066) and r=-0.144 (p=0.219), respectively. Discriminant validity: SNS Total scores were significantly statistically different according to the severity of the negative symptomatology rated by the CGI-SCH negative scale (p<0.001).

CONCLUSION

The SNS is a reliable and valid instrument to self-rate the five domains of negative symptoms in patients with schizophrenia and seems to be appropriate for use in everyday clinical practice as a complementary measure to the evaluation performed by the clinician.

Validation of the Arabic version of the "self-evaluation of negative symptoms" scale (SNS)

BACKGROUND

The self-evaluation of negative symptoms scale (SNS) is a new easy-to-use self-administered questionnaire allowing clinicians to understand the clinical and genetic factors affecting the negative symptoms in patients with schizophrenia. There was a need to translate and validate this scale in Arabic so that Arab-speaking patients benefit from it. Therefore, the aim of our study was to validate the Arabic version of the SNS in a sample of Lebanese patients with schizophrenia.

METHODS

The Arabic SNS was used to quantify the disability associated with negative symptoms in patients with schizophrenia (n = 206). Six weeks after completing the SNS, the participants were interviewed again to assess test-retest reproducibility. The validity was confirmed by factor analyses using the principal component analysis technique with a varimax rotation. The Positive and Negative Syndrome Scale (PANSS) was also assessed.

RESULTS

None of the items of the SNS scale were removed; all items converged over a solution of five factors that had an eigenvalue > 1, explaining a total of 66.01% of the variance (Cronbach's alpha = 0.879; test part). The mean total SNS score was 17.33 ± 8.43 for the "test", and 16.35 ± 7.50 for the "retest". The correlation coefficients between the SNS total score and the PANSS scale and subscales were as follows: total PANSS (r = 0.044; p = 0.530), positive PANSS score (r = - 0.106; p = 0.131), negative PANSS score (r = 0.204; p = 0.003), and general psychopathological PANSS score (r = 0.03; p = 0.530).

CONCLUSION

This study is the first to validate the Arabic version of the SNS in patients with schizophrenia. Using this scale would help improve treatment by correctly assessing negative symptoms, thus optimizing treatment options.

Associations between schizophrenia polygenic risk and apathy in schizophrenia spectrum disorders and healthy controls

OBJECTIVE

Apathy is a central predictor of a poor functional outcome in schizophrenia. Schizophrenia polygenic risk scores (PRSs) are used to detect genetic associations to key clinical phenotypes in schizophrenia. We explored the associations between schizophrenia PRS and apathy levels in schizophrenia spectrum disorders (n = 281) and matched healthy controls (n = 298), and further how schizophrenia PRS contributed in predicting apathy when added to premorbid and clinical factors in the patient sample.

METHOD

Schizophrenia PRSs were computed for each participant. Apathy was assessed with the Apathy Evaluation Scale. Bivariate correlation analyses were used to investigate associations between schizophrenia PRS and apathy, and between apathy and premorbid and clinical factors. Multiple hierarchical regression analyses were employed to evaluate the contributions of clinical variables and schizophrenia PRS to apathy levels.

RESULTS

We found no significant associations between schizophrenia PRS and apathy in patients and healthy controls. Several premorbid and clinical characteristics significantly predicted apathy in patients, but schizophrenia PRS did not.

CONCLUSION

Since the PRSs are based on common genetic variants, our results do not preclude associations to other types of genetic factors. The results could also indicate that environmentally based biological or psychological factors contribute to apathy levels in schizophrenia.

Associations of psychotic-like experiences, related symptoms, and working memory with functioning

This study examined the association of spatial working memory and attenuated psychotic-like experiences and related symptoms with social and role functioning. Findings from this study suggest that symptom dimensions and working memory impairment were associated with diminished functioning across a variety of domains. Specifically, negative symptoms and working memory impairment were inversely associated with both social and role functioning, whereas positive and disorganized symptoms showed inverse associations with social functioning only. Symptom dimensions did not moderate cognitive and functional variables, although working memory and attenuated clinical symptoms had an additive effect on functioning. Post-hoc analyses examining symptom dimensions simultaneously showed negative symptoms to be the variable most strongly predictive of overall functioning. These findings suggest that even in a non-clinical sample, sub-threshold psychosis symptoms and cognition may influence people’s social and role functioning.

Negative symptom severity at discharge from an index hospitalization and subsequent use of psychiatric care resources: A retrospective 1-year follow-up study on 450 patients with schizophrenia spectrum disorders

Negative symptoms of schizophrenia have a great impact on patients' functioning and are among the most important contributors to subject's disability. However, few studies have assessed the role of type and severity of symptomatology of schizophrenia on the psychiatric care resource utilization. We investigated if the clinical profile of patients at discharge from an index hospitalization might be associated with a different use of psychiatric care resources in the subsequent 1-year period in a large population of patients with schizophrenia spectrum disorders. Clinical records of 450 patients with schizophrenia spectrum disorders admitted in an acute psychiatric inpatient service and subsequently followed in the outpatient services of the same Department were reviewed. Patients with more severe negative symptoms at discharge from hospital showed a higher number and duration of hospitalizations in the 1-year follow-up, as well as a higher number of rehabilitative residential admissions than patients with milder severity of negative symptoms. The same was true for patients with predominant negative symptoms. A global resource utilization index indicated a higher use of psychiatric resources in patients with higher severity of negative symptoms. In conclusion, showing moderate to severe negative symptoms versus positive symptoms at discharge from a hospitalization for an acute exacerbation of schizophrenia spectrum disorder does predict a higher use of psychiatric care resources. This underlines the importance of relieving negative symptoms even in the acute phase of treatment and the need to develop more effective treatments for this symptom dimension.

Neurocognition and Social Cognition Predicting 1-Year Outcomes in First-Episode Psychosis

Cognitive performance at illness onset may predict outcomes in first-episode psychosis (FEP), and the change in cognition may associate with clinical changes. Cognitive testing was administered to 54 FEP participants 2 months after entering treatment and to 39 participants after 1 year. We investigated whether baseline cognition predicted 1-year outcomes beyond positive, negative, and affective symptoms and whether the trajectory of cognition associated with clinical change. Baseline overall neurocognitive performance predicted the 1-year social and occupational level, occupational status, and maintaining of life goals. The domain of processing speed associated with the 1-year remission, occupational status, and maintaining of life goals. Baseline social cognition associated with occupational status a year later and the need for hospital treatment during the 1st year after FEP. Most of the associations were retained beyond baseline positive and affective symptom levels, but when accounting for negative symptoms, cognition no longer predicted 1-year outcomes, highlighting how negative symptoms overlap with cognition. The trajectory of neurocognitive performance over the year did not associate with changes in symptoms or functioning. Cognitive testing at the beginning of treatment provided information on the 1-year outcome in FEP beyond positive and affective symptom levels. In particular, the domains of processing speed and social cognition could be targets for interventions that aim to improve the outcome after FEP.

Spanish validation of the self-evaluation of negative symptoms scale SNS in an adolescent population

BACKGROUND

Negative symptoms (NS) may be observed in the general population in an attenuated form and in high-risk mental states. However, they have been less studied in the general population than positive symptoms, in spite of their importance at the insidious onset of schizophrenia and their appearance before positive symptoms. This study aimed to analyze the empirical structure of the Spanish version of the Self-Evaluation of Negative Symptoms (SNS) Scale and find its psychometric properties and invariance of measurement across sex and age in a sample of adolescents.

METHODS

The sample consisted of 4521 adolescents (53.6% female) from 11 to 18 years of age.

RESULTS

Confirmatory Factor Analysis of the SNS confirmed an internal structure of five first-order factors by the characteristic dimensions of NS: avolition, social withdrawal, diminished emotional range, anhedonia, alogia, and one second-order factor which includes the total NS score. Multi-group confirmatory factor analysis showed that the scale was invariant across sex and age. Total scale reliability was adequate. A strong relationship was found between the SNS with depressive symptomatology, moderate with ideas of reference and low with aberrant salience.

CONCLUSION

The results back use of the Spanish version of the SNS scale for detection of NS in the general population of adolescents.

Specificity and sensitivity of the Self-assessment of Negative Symptoms (SNS) in patients with schizophrenia

OBJECTIVES

Negative symptoms can be present at any stage of schizophrenia but their evaluation remains challenging. Self-evaluations may be particularly useful in screening negative symptoms quickly and effectively. The purpose of this study was to determine the sensitivity, the specificity, and the threshold beyond which the negative symptoms are considered pathological in a comparative study between patients with schizophrenia and healthy subjects using the Self-assessment of Negative Symptoms (SNS).

METHODS

One hundred and nine patients with schizophrenia and schizoaffective disorders (DSM-5) and 99 healthy controls were included and evaluated with the SNS. AUROC analyses were performed to assess the discriminant performance of the SNS scale for screening negative symptoms in the whole sample of patients but also in 2 patient sub-samples without high scores of depression or negative symptoms.

RESULTS

The SNS (AUROC = 0.942 ± 0.046; p < 0.001) appears to be an appropriate screening tool for distinguishing between SZ and HC with a threshold value of 7, and the sensitivity and specificity were 92.7% (95CI = [86.1-96.8]) and 85.9% (95CI = [77.4-92.1]) respectively. A threshold at 7 was also observed in the samples without patients with high level of depressive or negative symptoms.

CONCLUSION

These results indicate that SNS might be a valuable tool for screening negative symptoms in clinical practice regardless the level of depressive and negative symptoms. Further studies using SNS in subjects at high risk for psychosis or with a first psychotic episode would be useful in the detection of negative symptoms.

A large European, multicenter, multinational validation study of the Brief Negative Symptom Scale

Negative symptoms represent an unmet need of treatment in schizophrenia. Although a consensus exists on negative symptom construct, and second generation assessment instruments reflecting the consensus are available, studies still rely upon old assessment instruments, that do not reflect recent conceptualizations and might limit progress in the search for effective treatments. This is often the case in the European context, where one of the challenges encountered in designing large studies is the availability of validated instruments in the many languages of the continent. To address this challenge and promote sound research on negative symptoms in Europe, the ECNP Schizophrenia Network coordinated a large multicenter, multinational validation study of the Brief Negative Symptom Scale (BNSS). Clinically-stable subjects with schizophrenia (SCZ, N = 249) were recruited from 10 European Countries. Apart from BNSS, subjects were administered the Positive and Negative Syndrome Scale (PANSS) and standardized instruments for depression, extrapyramidal symptoms and psychosocial functioning. Results showed an excellent internal consistency, convergent and discriminant validity of BNSS and replicated a 5 factor-model. A larger number of subjects with predominant negative symptoms, i.e. the target population for clinical trials, was identified by using the BNSS compared to the PANSS. Regression analysis showed that BNSS-avolition, a key negative symptom poorly assessed by PANSS, explained 23.9% of psychosocial functioning, while no combination of the PANSS core negative symptoms showed the same impact on functioning. The study demonstrated that BNSS has substantial advantages with respect to PANSS for the identification of the avolition domain and subjects with predominant negative symptoms.

Functional Connectivity of Corticostriatal Circuitry and Psychosis-like Experiences in the General Community

BACKGROUND

Psychotic symptoms are proposed to lie on a continuum, ranging from isolated psychosis-like experiences (PLEs) in nonclinical populations to frank disorder. Here, we investigated the neurobiological correlates of this continuum by examining whether functional connectivity of dorsal corticostriatal circuitry, which is disrupted in psychosis patients and individuals at high risk for psychosis, is associated with the severity of subclinical PLEs.

METHODS

A community sample of 672 adults with no history of psychiatric or neurological illnesses completed a battery of seven questionnaires spanning various PLE domains. Principal component analysis of 12 subscales taken from seven questionnaires was used to estimate major dimensions of PLEs. Dimension scores from principal component analysis were then correlated with whole-brain voxelwise functional connectivity maps of the dorsal striatum in a subset of 353 participants who completed a resting-state neuroimaging protocol.

RESULTS

Principal component analysis identified two dimensions of PLEs that accounted for 62.57% of variance in the measures, corresponding to positive (i.e., subthreshold delusions and hallucinations) and negative (i.e., subthreshold social and physical anhedonia) symptom-like PLEs. Reduced functional connectivity between the dorsal striatum and prefrontal and motor cortices correlated with more severe positive PLEs. Increased functional connectivity between the dorsal striatum and motor cortex was associated with more severe negative PLEs.

CONCLUSIONS

Consistent with past findings in patients and individuals at high risk for psychosis, subthreshold positive symptomatology is associated with reduced functional connectivity of the dorsal circuit. This finding suggests that the connectivity of this circuit tracks the expression of psychotic phenomena across a broad spectrum of severity, extending from the subclinical domain to clinical diagnosis.

Clarifying the overlap between motivation and negative symptom measures in schizophrenia research: A meta-analysis

Motivation and negative symptom research has recently been hampered by a series of inconsistent findings, leading to calls for a greater consensus on the type of measures used across studies. To inform this issue, we conducted a meta-analysis that quantified the association between motivation measures (self-report, performance-based) and clinician-rated negative symptom measures as well as a series of moderator analyses to develop a greater understanding of the measurement factors impacting this relationship. Forty-seven eligible studies with people with schizophrenia-spectrum disorders were included. Using a random-effects meta-analytic model, a small but significant overall effect size emerged between motivation and clinician-rated negative symptoms (r = -0.18). Several significant moderators were identified, including the generation of negative symptom measures such that there was a significantly stronger relationship between motivation and second-generation (r = -0.38) than first-generation negative symptom measures (r = -0.17). Further, the type of performance-based measure used moderated the relationship, with effort discounting tasks most strongly related to negative symptoms (r = -0.44). The domain of motivation assessed (intrinsic, extrinsic, amotivation) also moderated the relationship. These findings help to identify sources of inconsistencies observed in prior studies and point to both second-generation and effort discounting tasks as the most promising types of measures, particularly for those interested in validating motivation measures or assessing the effectiveness of motivation treatments. Although additional research is needed, our results suggest that using these measures may help to reduce inconsistencies across studies and move the field forward.

Self-assessment of negative symptoms - Critical appraisal of the motivation and pleasure - Self-report's (MAP-SR) validity and reliability

OBJECTIVE

The negative symptom domain remains a major challenge concerning treatment. A valid self-report measure could assist clinicians and researchers in identifying patients with a relevant subjective burden. The Motivation and Pleasure - Self Report (MAP-SR) derives from the CAINS and is supposed to reflect the "amotivation" factor of negative symptoms. We evaluated different aspects of the scale's reliability and validity. This is the first factorial analysis as well as the first analysis of test-retest reliability.

METHODS

We assessed three samples of subjects with schizophrenia or schizoaffective disorder (n = 93) and a broad spectrum of related domains.

RESULTS

We explored a 3-, 2- and 1-factor solution (explaining 50.93, 44.85 and 36.18% of variance, respectively). The factor "pleasure and hedonic activity" consists of eight items and was most robust; the factors "social motivation" and "motivation for work" were problematic. Test-retest reliability of the scale was adequate (r_S = 0.63, p = .005). Neither the MAP-SR nor the "pleasure and hedonic activities" factor are associated with the PANSS negative symptom scale. There are significant associations with the observer-rated CAINS-MAP scale, experiences of pleasure, and social cognition but none with functional outcome. Discriminant validity could not be established with regards to depression and extrapyramidal symptoms.

CONCLUSIONS

We found that the MAP-SR is adequate to assess anhedonia but is less suitable when assessing motivation. Therefore, we propose using the "pleasure and hedonic activity scale" to cover the "anhedonia" subdomain. We think the "motivation" part of the instrument requires reconstruction.

Revisiting the persistent negative symptoms proxy score using the Clinical Assessment Interview for Negative Symptoms

OBJECTIVE

The present study aimed to validate a severity cut-off of negative symptoms for persistent negative symptoms (PNS) identification using the Clinical Assessment Interview for Negative Symptoms (CAINS).

METHOD

A total of 206 patients with schizophrenia were recruited and divided into the PNS group (n = 57) and the Non-PNS group (n = 149) using PNS criteria based on the SANS and the SAPS. To determine the appropriate cut-offs on the CAINS in identifying PNS, Receiver Operating Characteristic (ROC) curve analysis was conducted in the PNS and Non-PNS groups.

RESULTS

Our results showed that the cutoffs for identifying PNS on the CAINS total score, the Motivation and Pleasure (MAP) subscale score and the Expression (EXP) subscale score were 25, 17, and 5 respectively. Area Under the Curve (AUC) analysis indicated excellent discrimination of the PNS group from the Non-PNS group using the cut-off for the CAINS total score. However, discrimination was somewhat better for the MAP subscale score than the EXP subscale score. The Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of the MAP subscale were 81.54% and 97.16%.

CONCLUSION

We found that the cut-off scores derived from the CAINS to identify PNS are comparable to existing scales. The CAINS offers an alternative means in identifying PNS patients in clinical trials that overcomes methodological and conceptual limitations of older scales.

Reliability and validity of the self-report version of the apathy evaluation scale in first-episode Psychosis: Concordance with the clinical version at baseline and 12 months follow-up

Negative symptoms have traditionally been assessed based on clinicians' observations. The subjective experience of negative symptoms in people with psychosis may bring new insight. The Apathy Evaluation Scale (AES) is commonly used to study apathy in psychosis and has corresponding self-rated (AES-S) and clinician-rated (AES-C) versions. The aim of the present study was to determine the validity and reliability of the AES-S by investigating its concordance with the AES-C. Eighty-four first-episode (FEP) patients completed the shortened 12-item AES-S and AES-C at baseline (T1) and 12 months (T2). Concordance was studied by degree of correlation, comparison of mean scores, and change and difference between diagnostic groups. The Positive and Negative Symptom Scale (PANSS) was used to study convergent and discriminative properties. High concordance was found between AES-S and AES-C at both T1 and T2 regarding mean values, change from T1 to T2, and the proportion with high levels of apathy. Both versions indicated high levels of apathy in FEP, while associations with PANSS negative symptoms were weaker for AES-S than AES-C. Controlling for depression did not significantly alter results. We concluded that self-rated apathy in FEP patients is in concordance with clinician ratings, but in need of further study.

The Brief Negative Symptom Scale: Validation in a multicenter Brazilian study

BACKGROUND

Negative symptoms are a core feature of schizophrenia. The Brief Negative Symptom Scale (BNSS) is a scale developed to measure negative symptoms in schizophrenia.

METHODS

The present study aimed to examine the construct validity of BNSS, by using convergent and divergent validities as well as factor analysis, in a Brazilian sample of 111 outpatients diagnosed with schizophrenia by DSM-5. Patients were evaluated by the Brazilian version of the BNSS and positive and negative subscales of the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Assessment of patients by both instruments revealed an excellent internal consistency (Cronbach's alpha = 0.938) or inter-rater reliability (ICC = 0.92), as well as a strong correlation between BNSS and Marder negative PANSS (r = 0.866) and a weak correlation of the instrument with the positive PANSS (r = 0.292), thus characterizing convergent and discriminant validities, respectively. The exploratory factor analysis identified two distinct factors, namely, motivation/pleasure and emotional expressivity, accounting for 68.63% of the total variance.

CONCLUSION

The study shows that the Brazilian version of the BNSS has adequate psychometric properties and is a reliable instrument for the assessment of negative symptoms in schizophrenia, either for clinical practice or research.

Negative symptoms of schizophrenia: new developments and unanswered research questions

Negative symptoms of schizophrenia are associated with poor functional outcome and place a substantial burden on people with this disorder, their families, and health-care systems. We summarise the evolution of the conceptualisation of negative symptoms, the most important findings, and the remaining open questions. Several studies have shown that negative symptoms might be primary to schizophrenia or secondary to other factors, and that they cluster in the domains of avolition-apathy and expressive deficit. Failure to take this heterogeneity into account might hinder progress in research on neurobiological substrates and discoveries of treatments for primary or enduring negative symptoms. Improvement in recognition and routine assessment of negative symptoms is instrumental for correct management of secondary negative symptoms that are amenable to treatment. If substantial progress is to be made in the understanding and treatment of negative symptoms, then advances in concepts and assessment should be integrated into the design of future studies of these symptoms.

The relationship between negative symptoms and depression in schizophrenia: a systematic review

OBJECTIVE

To provide an update on the evidence base for the nature of the relationship between negative symptoms and depressive features in people with schizophrenia, and propose new models that reflect their complex relationship.

METHOD

A systematic review following PRISMA guidelines. A total of 2210 articles were identified from EMBASE, PsychInfo and MEDLINE, and further two articles were hand-searched from references. Twenty-seven met inclusion criteria and were included in the review.

RESULTS

In schizophrenia, primary evidence suggests symptoms of low mood, suicidal ideation and pessimism have more specificity for depression whereas alogia and blunted affect may have more specificity as negative symptoms. Anhedonia, anergia and avolition may be common to both.

CONCLUSION

It may be possible to further distinguish depressive features from negative symptoms in schizophrenia when detailed phenomenology is considered. However, in a proposed dimensional model, these two domains continue to share certain phenomena, highlighting their close relationship.