The structure stability of negative symptoms: longitudinal network analysis of the Brief Negative Symptom Scale in people with schizophrenia.

BACKGROUND: The structure of negative symptoms of schizophrenia is still a matter of controversy. Although a two-dimensional model (comprising the expressive deficit dimension and the motivation and pleasure dimension) has gained a large consensus, it has been questioned by recent investigations. AIMS: To investigate the latent structure of negative symptoms and its stability over time in people with schizophrenia using network analysis. METHOD: Negative symptoms were assessed in 612 people with schizophrenia using the Brief Negative Symptom Scale (BNSS) at baseline and at 4-year follow-up. A network invariance analysis was conducted to investigate changes in the network structure and strength of connections between the two time points. RESULTS: The network analysis carried out at baseline and follow-up, supported by community detection analysis, indicated that the BNSS's items aggregate to form four or five distinct domains (avolition/asociality, anhedonia, blunted affect and alogia). The network invariance test indicated that the network structure remained unchanged over time (network invariance test score 0.13; P = 0.169), although its overall strength decreased (6.28 at baseline, 5.79 at follow-up; global strength invariance test score 0.48; P = 0.016). CONCLUSIONS: The results lend support to a four- or five-factor model of negative symptoms and indicate overall stability over time. These data have implications for the study of pathophysiological mechanisms and the development of targeted treatments for negative symptoms.

Defining negative symptoms remission in schizophrenia using the Brief Negative Symptom Scale.

INTRODUCTION: This study aimed to propose criteria for negative symptoms remission (NSR) in schizophrenia using the Brief Negative Symptom Scale (BNSS). MATERIAL AND METHODS: 274 participants were assessed on the Positive and Negative Syndrome Scale (PANSS), BNSS and Social and Occupational Functioning Assessment Scale (SOFAS). Two criteria for NSR on the BNSS were proposed - NSR based on the BNSS domains scores (NSRBNSS_DOMAINS) and NSR based on 5 key items of the BNSS (NSRBNSS_5ITEMS). A SOFAS score of 61 and above was considered as functional remission (FR). Logistic regressions were run to examine the association between FR and NSR. Receiver operating characteristic (ROC) curve analysis was performed for the NSR criteria on FR. Kappa agreement statistic was used to evaluate the agreement between the two NSR criteria. RESULTS: Eighty-nine (32.5%) participants fulfilled NSRBNSS_DOMAINS criterion whereas 70 (25.6%) participants fulfilled NSRBNSS_5ITEMS criterion. The two NSR criteria had substantial agreement (Kappa statistic=0.797) with each other. Sixty-one (25.3%) participants were in FR. FR was significantly associated with NSR, irrespective of the criterion used. To predict FR, the Area Under the Curve for NSRBNSS_DOMAINS and NSRBNSS_5ITEMS were 0.761 (CI: 0.696-0.826, p<0.001) and 0.723 (CI: 0.656-0.790, p<0.001), respectively. Hence, both NSR criteria demonstrated a fair ability to discriminate between functional remitters and non-remitters. CONCLUSIONS: Depending on the setting and needs, clinicians and researchers might employ either the full BNSS or an abbreviated 5-item BNSS scale to identify NSR in schizophrenia. More research is needed to further examine the validity of these criteria in schizophrenia.

Defining negative symptoms remission in schizophrenia using the Brief Negative Symptom Scale.

INTRODUCTION: This study aimed to propose criteria for negative symptoms remission (NSR) in schizophrenia using the Brief Negative Symptom Scale (BNSS). MATERIAL AND METHODS: 274 participants were assessed on the Positive and Negative Syndrome Scale (PANSS), BNSS and Social and Occupational Functioning Assessment Scale (SOFAS). Two criteria for NSR on the BNSS were proposed - NSR based on the BNSS domains scores (NSRBNSS_DOMAINS) and NSR based on 5 key items of the BNSS (NSRBNSS_5ITEMS). A SOFAS score of 61 and above was considered as functional remission (FR). Logistic regressions were run to examine the association between FR and NSR. Receiver operating characteristic (ROC) curve analysis was performed for the NSR criteria on FR. Kappa agreement statistic was used to evaluate the agreement between the two NSR criteria. RESULTS: Eighty-nine (32.5%) participants fulfilled NSRBNSS_DOMAINS criterion whereas 70 (25.6%) participants fulfilled NSRBNSS_5ITEMS criterion. The two NSR criteria had substantial agreement (Kappa statistic=0.797) with each other. Sixty-one (25.3%) participants were in FR. FR was significantly associated with NSR, irrespective of the criterion used. To predict FR, the Area Under the Curve for NSRBNSS_DOMAINS and NSRBNSS_5ITEMS were 0.761 (CI: 0.696-0.826, p<0.001) and 0.723 (CI: 0.656-0.790, p<0.001), respectively. Hence, both NSR criteria demonstrated a fair ability to discriminate between functional remitters and non-remitters. CONCLUSIONS: Depending on the setting and needs, clinicians and researchers might employ either the full BNSS or an abbreviated 5-item BNSS scale to identify NSR in schizophrenia. More research is needed to further examine the validity of these criteria in schizophrenia.

Association of Negative Symptoms of Schizophrenia Assessed by the BNSS and SNS Scales With Neuropsychological Performance: A Gender Effect.

Objective: The relationship between negative symptoms and neurocognitive performance in schizophrenia is well documented, but the mechanism of these connections remains unclear. The study aims to measure the relationship between the results on the new scales for the assessment of negative symptoms such as Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the results of some neurocognition tests. The second aim is to assess a possible gender effect on these associations. Methods: The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period (total PANSS score <80, unchanged pharmacological treatment in the last 3 weeks). They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for neuropsychological performance such as the Trail Making Test (TMT-A, TMT-B), Stroop Color-Word Interference Test, Verbal fluency tests (VFT), Category fluency test (CFT), and Digit Symbol Substitution Test (DSST). Results: Male patients obtained higher scores than females on some PANSS and BNSS items. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and CFT. In male patients, a significant positive correlation between the intensity of negative symptoms measured by the BNSS and the results of PSP with the Trail Making Test was observed. In female patients, we found a positive correlation between the results of BNSS and PSP with the Stroop Color-Word Interference Test. Conclusion: The obtained results confirm the relationship between negative symptoms and neurocognition in schizophrenia patients. However, in male and female patients such association was observed for different cognitive domains. Further research is needed to explain the nature of these differences.

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.

Raloxifene augmentation in men and women with a schizophrenia spectrum disorder: A study protocol.

Although acute psychotic symptoms are often reduced by antipsychotic treatment, many patients with schizophrenia are impaired in daily functioning due to the persistence of negative and cognitive symptoms. Raloxifene, a Selective Estrogen Receptor Modulator (SERM) has been shown to be an effective adjunctive treatment in schizophrenia. Yet, there is a paucity in evidence for raloxifene efficacy in men and premenopausal women. We report the design of a study that aims to replicate earlier findings concerning the efficacy of raloxifene augmentation in reducing persisting symptoms and cognitive impairment in postmenopausal women, and to extend these findings to a male and peri/premenopausal population of patients with schizophrenia. The study is a multisite, placebo-controlled, double-blind, randomised clinical trial in approximately 110 adult men and women with schizophrenia. Participants are randomised 1:1 to adjunctive raloxifene 120 mg or placebo daily during 12 weeks. The treatment phase includes measurements at three time points (week 0, 6 and 12), followed by a follow-up period of two years. The primary outcome measure is change in symptom severity, as measured with the Positive and Negative Syndrome Scale (PANSS), and cognition, as measured with the Brief Assessment of Cognition in Schizophrenia (BACS). Secondary outcome measures include social functioning and quality of life. Genetic, hormonal and inflammatory biomarkers are measured to assess potential associations with treatment effects. If it becomes apparent that raloxifene reduces psychotic symptoms and/or improves cognition, social functioning and/or quality of life as compared to placebo, implementation of raloxifene in clinical psychiatric practice can be considered.

Validation of the Brief Negative Symptom Scale in Korean patients with schizophrenia.

INTRODUCTION: The Brief Negative Symptom Scale (BNSS) was developed based on the current consensus on negative symptoms. We validated the Korean version of the BNSS (K-BNSS) and explored the factor structure of negative symptoms among 173 Koreans with schizophrenia. METHODS: Clinical interviews and neurocognitive assessments were administered to evaluate the factor structure, validity, and reliability of the K-BNSS. RESULTS: The five-factor model of the K-BNSS showed excellent reliability and validity. DISCUSSION: Our findings confirm that the K-BNSS is a promising instrument for assessing negative symptoms of schizophrenia, and that negative symptoms are best conceptualized in the form of five domains.

Polish version of the Brief Negative Symptom Scale (BNSS). / Polska wersja Krótkiej Skali Objawów Negatywnych (Brief Negative Symptom Scale ­ BNSS).

OBJECTIVES: To create a Polish adaptation of the Brief Negative Symptom Scale (BNSS), to assess the internal consistency of the Polish version of the BNSS, and to make correlations between the BNSS scores and the Positive and Negative Syndrome Scale (PANSS) in the group of patients with schizophrenia. METHODS: The procedure of Polish adaptation of the assessment form (Scoresheet) of the BNSS, comprising 13 items organized in 6 subscales (anhedonia, lack of proper distress, asociality, avolition, blunted affect, and alogia), as well as the Manual and the Workbook of the scale was carried out. Psychometric tests were performed in 40 patients with paranoid schizophrenia (20 men and 20 women), aged 44±13 years, with illness duration of 17±10 years, and severity of symptoms on the PANSS 56±16 points, receiving unchanged pharmacological treatment in the last three months. RESULTS: The Polish version was accepted by the authors of the scale. The reliability analysis showed high values of the Cronbach's alpha coefficient both for the whole scale (0.97) and for individual subscales (0.74-0.93). The BNSS and its subscales showed a high significant correlation with the total PANSS score and with the PANSS negative symptom subscale, both original and modified. CONCLUSIONS: The obtained results indicate good psychometric properties of the Polish version of the BNSS and its possible usefulness in the study of negative symptoms of schizophrenia conducted in Poland.

Inverse association between negative symptoms and body mass index in chronic schizophrenia.

BACKGROUND: We investigated whether negative symptoms, such as poor motivation or anhedonia, were associated with higher body mass index (BMI) in stable patients with schizophrenia chronically treated with antipsychotic medication. METHODS: 62 olanzapine- or clozapine-treated patients with illness duration of at least four years were selected from an international multicenter study on the characterization of negative symptoms. All participants completed the Brief Negative Symptom Scale (BNSS) and the Positive and Negative Syndrome Scale (PANSS). Bivariate correlations between BMI and negative symptoms (BNSS) were explored, as well as multiple regression analyses. We further explored the association of two principal component factors of the BNSS and BMI. Subsidiary analyses re-modeled the above using the negative symptoms subscale of the PANSS and the EMSLEY factor for negative symptoms for convergent validity. RESULTS: Lower negative symptoms (BNSS score) were associated with higher BMI (r=-0.31; p=0.015). A multiple regression analysis showed that negative symptoms (BNSS score) and age were significant predictors of BMI (p=0.037). This was mostly driven by the motivation/pleasure factor of the BNSS. Within this second factor, BMI was negatively associated with anhedonia (r=-0.254; p=0.046) and asociality (r=-0.253; p=0.048), but not avolition (r=-0.169; p=0.188). EMSLEY score was positively associated with BNSS (r=0.873, p<0.001), but negatively associated with BMI (r=-0.308; p=0.015). The association between PANSS and BMI did not reach significance (r=-224, p=0.080). CONCLUSIONS: We conclude that lower negative symptoms were associated with higher BMI (assessed using both the BNSS and EMSLEY) in chronic stable schizophrenia patients, mostly due to lower anhedonia and asociality levels.