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

Systematic Review of Self-Assessment Scales for Negative Symptoms in Schizophrenia

Background/Objectives: Negative symptoms (NSs) significantly impair the outcome of schizophrenia, primarily due to their effect on quality of life and their resistance to pharmacological treatments. Several scales have been developed to assess the various dimensions of NSs, including avolition, anhedonia, alogia, social withdrawal, and blunted affect. While observer-rated scales are the most commonly used, self-assessment tools remain underutilized. However, self-assessments offer a promising approach for gaining insights into the personal experiences of individuals. The objective of this review was to identify and report the psychometric properties of self-assessment scales for NSs that are relevant for both research and clinical practice, with a focus on tools that assess multiple domains of NSs in order to support comprehensive evaluations and tailored therapeutic strategies. Methods: We conducted an exhaustive literature review following PRISMA guidelines to identify self-evaluation scales that evaluate several domains of NSs in the MEDLINE and Web of Science databases. The COSMIN checklist was used to assess the methodological quality of each tool. Results: Our review identified five self-assessment scales. Among these, two scales received a Grade A recommendation for use in clinical or research practice: the Self-evaluation Negative Symptom (SNS), which assesses the five domains of NSs, and the Motivation And Pleasure Scale Self-report (MAP-SR), which evaluates anhedonia, avolition, and social withdrawal. Conclusions: The SNS and the MAP-SR are the only tools with sufficient psychometric properties, making them reliable for use in both research and clinical practice. Despite the development of self-assessment tools for NSs, their integration into research and clinical settings remains limited, highlighting the need for increased utilization to enhance the understanding and management of these symptoms.

Dutch Validation of the Self-Evaluation of Negative Symptoms Scale (SNS)

BACKGROUND/OBJECTIVES

Negative symptoms in schizophrenia spectrum disorders are related to impaired social functioning and lower quality of life, making accurate assessment important. To date, most tools for assessing negative symptoms are observational, which can be influenced by the raters' experience and opinion. Self-rating scales, like the Self-Evaluation of Negative Symptoms (SNS), could complement observer ratings by adding information from the patient's perspective. Here, we aim to evaluate the psychometric properties of the Dutch translation of the SNS and the relationship between the SNS and functional outcomes.

METHODS

The SNS was added to the Pharmacotherapy Monitoring Outcome Survey (PHAMOUS)-protocol for adults with a DSM-5 classification of a disorder in the psychosis spectrum. Internal consistency was assessed by Cronbach's alpha. Confirmatory factor analysis (CFA) was used to evaluate the construct validity of the five subscales of the SNS. Correlational analyses were performed between the SNS and the Positive and Negative Syndrome Scale (PANSS), the Health of Nation Outcomes Scales (HoNOS), the Global Assessment of Functioning (GAF), Functional Remission tool (FR) and the Manchester Short Assessment of Quality of Life (ManSA).

RESULTS

A total of 247 patients participated in this study. Internal consistency was good (α = 0.87). CFA confirmed the five-factor structure of the SNS. The SNS was significantly correlated (all p < 0.001) with the PANSS positive (r = 0.31), PANSS negative (r = 0.33), HoNOS (r = 0.37), FR (r = 0.27) and the ManSA (r = -0.40).

CONCLUSIONS

The Dutch SNS shows good psychometric properties and is related to functional outcomes and quality of life. The SNS can be valuable in complementing current observational-based instruments, and future research may investigate whether the SNS can be used as a standalone measurement tool for the assessment of negative symptoms.

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.

Impaired Effort Allocation in Patients with Recent-Onset Schizophrenia and Its Relevance to Negative Symptoms Assessments and Persistent Negative Symptoms

(1) Background: Our aims in this study were (i) to compare effort allocation capacity measured between patients with recent-onset schizophrenia (SCZ) and healthy controls (HCs), (ii) within the SCZ, to investigate the association of effort allocation capacity with negative symptoms (NS), and (iii) to compare this association with the type of NS scale used. (2) Methods: Thirty-one patients with SCZ and 30 HCs participated in the study. The NS was examined using an older-generation (Scale for the Assessment of Negative Symptoms, SANS), a newer-generation (Brief Negative Symptoms Scale, BNSS), and a self-rated (Self-evaluation of Negative Symptoms Scale, SNS) negative symptom scale, as well as longitudinally by using persistent NS (PNS) distinction. (3) Results: The SCZ group was less willing to expend effort in high/moderate-probability and -magnitude conditions but more in low-probability and -magnitude conditions. A general reduction in effort allocation capacity was also present. Patients with PNS were less likely to choose hard tasks than non-PNS patients. Clinician-rated scales correlated with 50% probability and moderate-reward-magnitude conditions. Correlations with the SNS were minimal. (4) Conclusions: Our findings suggest that patients with SCZ may show a general reduction in effort allocation capacity and make inefficient choices, although they are not totally reward-insensitive. The effects of NS on effort expenditure can be more pronounced when the rewarding stimulus is vague.