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

Exploring negative symptoms heterogeneity in patients diagnosed with schizophrenia and schizoaffective disorder using cluster analysis

BACKGROUND

Dissecting the heterogeneity of schizophrenia may help foster progress in understanding its etiology and lay the groundwork for the development of new treatment options for primary or enduring negative symptoms (NS). In this regard, the present study aimed to: (1) to use cluster analysis to identify subgroups of Lebanese patients diagnosed with either schizophrenia or schizoaffective disorder based on NS clusters, and (2) to relate the statistically-derived subgroups to clinically relevant external validators (including measures if state and trait depression, stigma, insight, loneliness, social support).

METHOD

A total of 202 adult long-stay, chronic, and clinically remitted patients (166 diagnosed with schizophrenia and 36 with schizoaffective disorder) were enrolled. A cluster analysis approach was adopted to classify patients based on the five NS domains social withdrawal, emotional withdrawal, alogia, avolition and anhedonia.

RESULTS

A three-cluster solution was obtained based on unique NS profiles, and divided patients into (1) low NS (LNS; 42.6%) which characterized by the lowest mean scores in all NS domains, (2) moderate NS (MNS; 25.7%), and (3) high NS (HNS; 31.7%). Post-hoc comparisons showed that depression (state and trait), loneliness and social support could accurately distinguish the schizophrenia subgroups. Additionally, individuals in the HNS cluster had longer duration of illness, longer duration of hospitalization, and were given higher dosages of antipsychotic medication compared to those in the other clusters, but these differences did not achieve the statistical significance.

CONCLUSION

Findings provide additional support to the categorical model of schizophrenia by confirming the existence of three alternate subtypes based on NS. The determination of distinct NS subgroups within the broad heterogeneous population of people diagnosed with schizophrenia may imply that each subgroup possibly has unique underlying mechanisms and necessitates different treatment approaches.

Validity and reliability of a Chinese version of the self-evaluation of negative symptoms

The negative symptoms of schizophrenia can be present at any clinical stage, but evaluating the negative symptoms always remains challenging. To screen the negative symptoms effectively, self-evaluation should be introduced. To date, professional psychiatrists used almost all of the scales available to screen the negative symptoms but could not obtain an accurate outcome. At the same time, an advanced self-assessment scale is needed to accompany the patients' self-feeling-based treatment strategies to understand their feelings about their symptoms. Hence, Chinese self-evaluation of negative symptoms (SNS) should be introduced in China. This study aims to examine the validity and reliability of the Chinese version of SNS. Two hundred patients with schizophrenia were included in this study and were evaluated entirely with the self-assessed negative symptoms by the Chinese version. The correlation analysis was performed between SNS and the Scale for Assessment of Negative Symptoms (SANS) to assess the criterion validity of SNS for screening negative symptoms. Exploratory factor analysis was used to determine the constructive validity of the SNS. Two senior professional psychiatrists were involved in this assessment based on their clinical experience and capability to define the severity of the negative symptoms. Receiver operating characteristic curve (ROC) analysis was performed to assess the cutoff point of SNS. Cronbach's alpha coefficient and intraclass correlation (ICC) coefficient were used to determine the reliability of SNS. We have the following findings: The Chinese version of SNS demonstrated a significant correlation with the SANS (r = .774, p < .05). Exploratory factor analysis demonstrated that the factor loading varies from .442 to .788. ROC analysis demonstrated that at SNS ≥ 8, the patients demonstrated a mild severity of negative symptoms, and at SNS ≥ 15, the patients demonstrated a severe severity of negative symptoms. Subsequently, 9 < SNS < 14 was defined as a moderate severity of negative symptoms. The Cronbach's alpha and ICC coefficients of the Chinese version SNS were .877 and .774, respectively. Our results showed that the acceptable validity and reliability of the Chinese version of SNS confirmed that SNS is an ideal tool for self-assessment of the negative symptoms in patients with schizophrenia.

The Self-Evaluation of Negative Symptoms in Differentiating Deficit Schizophrenia: The Comparison of Sensitivity and Specificity with Other Tools

INTRODUCTION

Psychometric properties of the Self-evaluation of Negative Symptoms (SNS) in subjects with the deficit subtype of schizophrenia (SCZ-D) have not been investigated so far. This study had the following aims: (1) to assess psychometric properties of SNS in subjects with SCZ-D and (2) to explore the usefulness of SNS, in comparison with other clinical characteristics, in screening for SCZ-D.

METHODS

Participants were 82 stable outpatients with schizophrenia, including 40 individuals with SCZ-D and 42 individuals with the non-deficit subtype (SCZ-ND).

RESULTS

Internal consistency was acceptable-to-good in both groups. Factor analysis revealed two dimensions (apathy and emotional). There were significant positive correlations of the SNS total score with the subscore of negative symptoms from the Positive and Negative Syndrome Scale (PANSS) and significant negative correlations with scores of the Social and Occupational Functioning Assessment Scale (SOFAS) in both groups, indicating good convergent validity. The following measures were found to be appropriate screening tools for differentiating SCZ-D and SCZ-ND (p < 0.001): the SNS total score (area under the curve [AUC]: 0.849, cut-off ≥16, sensitivity: 80.0%, specificity: 78.6%), the PANSS subscore of negative symptoms (AUC: 0.868, cut-off ≥11, sensitivity: 90.0%, specificity: 78.6%), and the SOFAS (AUC: 0.779, cut-off ≤59, sensitivity: 69.2%, specificity: 82.5%). Also, adding the SOFAS (cut-off ≤59) to the SNS (cut-off: ≥16) further improved sensitivity and specificity (AUC: 0.898, p < 0.001, sensitivity = 87.5%, specificity = 82.2%). Cognitive performance and age of psychosis onset were not found to be suitable measures for differentiating SCZ-D and SCZ-ND.

CONCLUSION

The present findings indicate that the SNS has good psychometric properties in subjects with SCZ-D and those with SCZ-ND. Moreover, the SNS, the PANSS, and the SOFAS might be used as screening tools for SCZ-D.

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.

European Validation of the Self-Evaluation of Negative Symptoms (SNS): A Large Multinational and Multicenter Study

BACKGROUND

Negative symptoms are usually evaluated with scales based on observer ratings and up to now self-assessments have been overlooked. The aim of this paper was to validate the Self-evaluation of Negative Symptoms (SNS) in a large European sample coming from 12 countries. We wanted to demonstrate: (1) good convergent and divergent validities; (2) relationships between SNS scores and patients' functional outcome; (3) the capacity of the SNS compared to the Brief Negative Symptom Scale (BNSS) to detect negative symptoms; and (4) a five-domain construct in relation to the 5 consensus domains (social withdrawal, anhedonia, alogia, avolition, blunted affect) as the best latent structure of SNS.

METHODS

Two hundred forty-five subjects with a DSM-IV diagnosis of schizophrenia completed the SNS, the Positive and Negative Syndrome Scale (PANSS), the BNSS, the Calgary Depression Scale for Schizophrenia (CDSS), and the Personal and Social Performance (PSP) scale. Spearman's Rho correlations, confirmatory factor analysis investigating 4 models of the latent structure of SNS and stepwise multiple regression were performed.

RESULTS

Significant positive correlations were observed between the total score of the SNS and the total scores of the PANSS negative subscale (r = 0.37; P < 0.0001) and the BNSS (r = 0.43; p < 0.0001). SNS scores did not correlate with the level of insight, parkinsonism, or the total score of the PANSS positive subscale. A positive correlation was found between SNS and CDSS (r = 0.35; p < 0.0001). Among the 5 SNS subscores, only avolition subscores entered the regression equation explaining a lower functional outcome. The 1-factor and 2-factor models provided poor fit, while the 5-factor model and the hierarchical model provided the best fit, with a small advantage of the 5-factor model. The frequency of each negative dimension was systematically higher using the BNSS and the SNS vs. the PANSS and was higher for alogia and avolition using SNS vs. BNSS.

CONCLUSION

In a large European multicentric sample, this study demonstrated that the SNS has: (1) good psychometric properties with good convergent and divergent validities; (2) a five-factor latent structure; (3) an association with patients' functional outcome; and (4) the capacity to identify subjects with negative symptoms that is close to the BNSS and superior to the PANSS negative subscale.

Mindfulness, cognitive fusion, and self-compassion in patients with schizophrenia spectrum disordersA cross-sectional study

In the last decades, third wave approaches in cognitive-behavioral therapies (CBT) have shown effectiveness in treating several mental disorders, including schizophrenia spectrum disorders (SSD). Three crucial processes associated with clinical changes in patients include mindfulness, psychological flexibility (PF) and self-compassion (SC). PF is generally assessed by cognitive fusion (CF), a negative formulated key process of PF. The current study encompasses a cross-sectional design to examine the interplay of mindfulness, CF, SC and symptom severity in SSD. It was hypothesized that mindfulness is negatively correlated with symptom severity, CF mediates the negative relation between mindfulness and symptom severity, and SC moderates the link between mindfulness and CF. In total, 79 persons with SSD were recruited at the Department of Psychiatry and Neurosciences at the Charité - Universitätsmedizin Berlin. Correlations, as well as moderated mediation analyses, were performed using the analysis modeling tool PROCESS with total symptom severity and negative symptom severity as outcome variables, measured by the Positive and Negative Syndrome Scale (PANSS) and the Self-Evaluation of Negative Symptoms Scale (SNS). Results show that the moderated mediation hypothesis was confirmed for negative symptom severity assessed by SNS, however, not for total symptom severity assessed by PANSS. In general, the association between mindfulness and CF was stronger for participants with higher SC scores in our data. Future studies should investigate the relationship between mindfulness, SC, and PF regarding symptom severity in SSD in longitudinal designs while considering the impact on different outcomes and differences regarding assessment tools.

Validity and reliability of a Persian version of the self- evaluation of negative symptoms (SNS)

AIM

The Self-evaluation of Negative Symptoms (SNS) has been developed to allow schizophrenia patients to evaluate themselves in five dimensions of negative symptoms. The present study aimed to examine psychometric properties of the Persian version of SNS.

METHODS

A group of 50 patients with schizophrenia and a group of 50 healthy controls received the Persian-SNS. Severity of negative symptoms were evaluated by the Scale for Assessment of Negative symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS).

RESULTS

The results showed that the Cronbach's alpha for the Persian SNS was 0.95. The Persian-SNS and its subscales showed significant positive correlations with the total SANS score and SANS subscales as well as BPRS negative subscale, thus confirming the validity of the scale. Finally, the Persian-SNS showed the ability to discriminate patients with schizophrenia from healthy controls.

CONCLUSION

The acceptable properties of the Persian version of SNS demonstrated that it is a practical tool for screening negative symptoms in Persian-speaking schizophrenia patients.

Negative symptoms in schizophrenia, assessed by the brief negative symptom scale, self-evaluation of negative symptom scale, and social cognition: a gender effect

OBJECTIVE

Negative symptoms of schizophrenia can be related to social cognition. The aim was to measure a relationship between the results on the new scales for the assessment of negative symptoms such as the Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the measures of social cognition.

METHODS

The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period. They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for social cognition such as the Facial Emotion Identification Test, Reading the Mind in Eyes Test, Strange Stories and Faux Pas Test.

RESULTS

Male patients obtained higher scores than females when assessed by the BNSS. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and both parts of the Faux Pas test and obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in males.

CONCLUSIONS

Gender differences were found in the assessment of negative symptoms by a clinical scale and the relationship between negative symptoms and social cognition.KEY POINTSFemale patients scored better in the BNSS, PSP and both parts of the Faux-Pas testGender differences were present in the assessment of negative symptoms by clinical (BNSS) but not the self-assessment (SNS) scale.Female patients obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in male subjects.

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.

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.