Personality traits and disability in multiple sclerosis: The role of type D personality

The Type D personality has been linked to worse outcomes in chronic diseases, but its role in multiple sclerosis (MS) disability is not well established. The study aimed to compare demographic and clinical characteristics of MS patients with and without a Type D personality and to explore their associations with Type D personality.

In this cross-sectional study, 350 people with MS (PwMS) were recruited from a tertiary MS clinic in Iran from August 2024 to May 2025. Demographic and clinical data, including MS subtype and disability measured by the Expanded Disability Status Scale (EDSS), were collected through clinical evaluation and medical records. Personality traits were assessed using the Persian version of the NEO Five-Factor Inventory, and Type D personality was defined as high Neuroticism (T-score ≥ 60) and low Extraversion (T-score ≤ 40). Group comparisons and univariate and multivariate regression analyses were performed to examine associations between Type D personality and clinical and demographic characteristics.

Among participants (70.9 % female, median age 38 years), 14.9 % had Type D personality. The prevalence of Type D personality was 11.1 % in relapsing-remitting MS and 32.2 % in progressive MS. Compared to PwMS without Type D personality, PwMS with Type D personality had higher median EDSS (2.5 vs. 1.0, p < 0.001), and greater EDSS worsening (delta EDSS: 1.0 vs. -0.5, p < 0.001). Regression analysis showed that having a Type D personality (B = 0.87, 95 % CI: 0.61-1.14, p < 0.001) and the EDSS score recorded at the initial clinical evaluation near disease onset (B = 0.91, 95 % CI: 0.76-1.06, p < 0.001) were associated with current EDSS.

Type D personality was more prevalent in people with progressive MS and was associated with higher disability levels. These findings support incorporating personality assessments into MS care and exploring targeted psychosocial strategies for at-risk patients.