Assessment of negative symptoms in male and female schizophrenia patients using the Polish version of the Brief Negative Syndrome Scale and Self-evaluation of Negative Symptoms

Introduction
The assessment of the severity of negative symptoms is an important diagnostic element in schizophrenia. Recently, two new diagnostic tools have been introduced, included in second-generation scales: the Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS). The aim of the study is to evaluate the differences between men and women in the severity of negative symptoms using the Polish versions of BNSS and SNS.

Material and methods
The study involved 40 patients (20 men, 20 women) with paranoid schizophrenia (ICD-10). They were in the period of symptomatic stabilisation (PANSS < 80 points) and had received unchanged pharmacological treatment during the preceding three months. The assessment of the severity of the disease symptoms was made using the PANSS. The Polish versions of the BNSS and SNS were used to assess negative symptoms.

Results
There were no gender differences regarding the age and duration of the illness. The mean total PANSS score was higher in men. Negative symptoms evaluated by the BNSS showed significantly greater scores in men compared to women in asociality (internal experience and total), avolition (internal experience and total), and alogia (spontaneous elaboration). There were no gender differences using the SNS.

Conclusions
The results indicate the existence of significant gender differences in the assessment of negative symptoms in three subscales of negative symptoms, assessed by the BNSS. The lack of such differences performing the self-assessment may indicate a tendency of clinicians to assign higher scores to men for asociality, avolition, and alogia.