The Characteristics of Primary and Secondary Negative Symptoms in Patients with Schizophrenia, and Their Impact on Social Functioning

Aim. To study the clinical characteristics of primary and secondary poles of negative disorders, determine the role of inflammation in their formation, and assess the impact of their manifestations on the social functioning of patients with schizophrenia. Design. Cross-sectional study. Materials and Methods. The study included 42 patients diagnosed with paranoid schizophrenia with a disease duration of more than 3 years. The median age of patients was 40 (29–47) years. Patients were at the stage of remission formation, and negative symptoms dominated their clinical presentation. Clinical-anamnestic, clinical-psychopathological, and psychometric examination methods were applied. Psychometric tools included the Positive and Negative Syndrome Scale, Brief Negative Symptom Scale, Calgary Depression Scale for Schizophrenia Patients, Extrapyramidal Symptoms Rating Scale, and Personal and Social Performance Scale. Based on complete blood count data, systemic inflammation indices were calculated: neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the systemic immune-inflammation index. Results. Cluster analysis identified two clusters depending on the predominance of primary or secondary negative symptoms (SNS). Despite comparable severity of negative symptoms across the clusters, the group with predominant SNS (characterized by pronounced depressive and extrapyramidal symptoms) demonstrated significantly better social functioning (p = 0.002). No significant correlations were found between negative symptoms and the level of systemic inflammation. Multiple linear regression analysis revealed a statistically significant influence of the severity of negative and depressive symptoms, as well as disease duration, on the social and personal functioning of schizophrenia patients (F = 17.1, p < 0.001, R2 = 0.64, AIC = 248, d = 1.64). Conclusion. According to the obtained data, dominant negative symptoms in the clinical picture of schizophrenia patients can be conceptualized within a two-cluster model based on the predominance of primary or secondary components of negative disorders. In patients with dominant negative symptoms, the presence of depressive disturbances acts as a predictor of better social functioning. Keywords: paranoid schizophrenia, negative symptoms, secondary negative symptoms, social functioning, cluster analysis, neuroinflammation.