Interactive Role of Reinforcement Sensitivity (BIS/BAS) and Personality Traits in Predicting the Severity of Multiple Sclerosis Disease

Introduction: Multiple sclerosis (MS) is the most common neurologic disorder in young and middle-aged individuals worldwide. This disorder can afflict any part of the Central Neural System (CNS), optic nerves, brainstem, cerebellum and the spinal cord. The present study was an attempt to investigate the interactive role of reinforcement sensitivity (BIS/BAS) and personality traits in predicting the severity of the MS disease.Methods: The study was a correlational enquiry in which 162 patients with MS were selected by purposive sampling in Shiraz, Iran. The data were collected using NEO Five Factor Inventory (NEO-FFI), Jackson-5 scale, and Expanded Disability Status Scale (EDSS) questionnaires and were finally analyzed using Pearson correlation coefficient and multiple regression. The SPSS software version 21 (SPSS, Inc., Chicago, IL, USA) was used for the statistical analysis.Results: The results showed that indicators of personality traits (F chanch = 10.562, p < 0.01) and reinforcement sensitivity (F chanch = 1.567, p < 0.01) significantly predicted the scores of expanded disability status of the MS disease. The interaction between the indicators of personality traits and reinforcement sensitivity factors significantly increased the variance determined in the criterion variable (F chanch = 54.218; 10.214, p < 0.01).Conclusions: The results indicated that the interaction between personality traits and reinforcement sensitivity factors increases the risk of the growth of the MS disease.