Objective. To explore the relationship between the indicators of quality of life (QOL) and social functioning (SF) of patients with schizophrenia with clinical and socio-demographic characteristics, indicators of cognitive functions and the severity of disease symptoms, using mathematical modeling methods. Material and methods. The sample consisted of 300 patients with paranoid schizophrenia (aged 18-50 years, disease duration at least 5 years; total PANSS score <120). Clinical-psychopathological, psychometric and mathematical methods were used. A mathematical model based on the construct developed by the authors called the «Disease Burden Factor» (Factor «B») was utilized. Results and Conclusion. Statistically significant correlations of factor “B” with age, the time of disease onset, seeking psychiatric help and diagnosis, the length of hospital admissions in the past 12 months and PANSS and BACS scores were established. Factor «B» clusters of «prosperous» and «dysfunctional» patients, significantly differing in the frequency of exacerbations of the disease, its total duration, and indicators of QOL-SM, PSP, PANSS, BACS, were distinguished. The conclusion about the reliability and sensitivity of a new toolbox - Factor «B» for exploring the mutual influence of heterogeneous factors affecting the trajectory of patients with schizophrenia was made.