Multiple Sclerosis (MS)—an inflammatory demyelinating disease of the central nervous system—is a chronic disease that has been associated with different personality displays in previous studies (Maggio et al., 2020). Neurological diseases can influence personality traits and change people's behavior, cognition, emotional functioning, and vice versa. For example, over time, people with Parkinson's disease have been found to experience decreased extraversion and openness and increased neuroticism (Santangelo et al., 2018), while people with Huntington's disease may experience increased neuroticism and conscientiousness (Larsen et al., 2016). Additionally, men and women with traumatic brain injury may exhibit alteration in several personality traits, with some studies indicating a trend toward decreased agreeableness and increased neuroticism (Max et al., 2000; Rieger, 2015). However, the consequences of neurological diseases on personality traits may vary depending on the type, severity, and duration of the condition; thus, factors such as age, gender, and the presence of previous mental disorders (e.g., anxiety and depression) can also alter the mutual influences and consequences of neurological diseases on personality. Comprehending the changes in personality traits related to neurological diseases can have implications for treatment and care, such as interventions targeting distinct personality traits may be more efficacious in enhancing the quality of life and functional outcomes for those groups. In addition, understanding how personality might protect people from the debilitating effects of neurological diseases assists in our understanding of who may require additional care.

Among neurological diseases, MS is one that can have significant effects on a person's physical, cognitive, and emotional functioning. While there are limited investigations on the consequence of MS on personality traits, previous evidence shows that people with MS exhibit personality changes, with an increase in neuroticism and a decrease in extraversion and conscientiousness (Maggio et al., 2020). Neuroticism, which is a tendency to experience negative emotions such as anxiety and depression, is particularly heightened in persons with MS (pwMS); such increase could be related to the physical symptoms of the disease (i.e., pain and fatigue), as well as the psychological effect of living with a chronic illness. The decrease in extraversion and conscientiousness, which are associated with sociability and self-discipline, respectively, could be associated with the challenges of living with MS (i.e., reduced mobility and cognitive impairment; Maggio et al., 2020).

The Five-Factor Model (FFM) is a widely acknowledged and empirically supported framework for comprehending human personality (McCrae and John, 1992). Despite showing sound evidence in distinct countries and cultures, research has also revealed that there can be distinctions in how the FFM manifests in different groups (McCrae and Alik, 2002). Characteristics, such as age, education level, and occupation, are related to differences in personality traits (Roberts and Mroczek, 2008). Men, for example, tend to score higher on instruments of extraversion and lower on measures of agreeableness and neuroticism, while women tend to score higher on agreeableness and neuroticism (Costa et al., 2001; Schmitt et al., 2008). Considering these possible contrasts when interpreting personality assessment results can lead to more precise and culturally sensitive interpretations of personality and help guide the proposition of interventions to pwMS.

In this study, we sought to explore how demographic variables (i.e., age, sex, and education) and personality traits predict current vocation, information processing speed, anxiety and depression symptoms, and disability level in pwMS.