Personality Traits and Their Association With Medication Non-Adherence in Patients With Multiple Sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system that typically requires lifelong treatment. The management of MS relies on a multifaceted approach that includes disease-modifying therapy along with the treatment of acute relapses, MS-related symptoms, and comorbid conditions. Medication adherence is crucial for achieving favorable treatment outcomes, but non-adherence remains a prevalent issue. The aim of this study was to explore how individual personality traits and other factors contribute to suboptimal adherence in people with MS (pwMS).

A total of 397 pwMS were included in this cross-sectional study. Personality traits were assessed through patient questionnaires using the NEO Five-Factor Inventory and the Temperament and Character Inventory-Revised. Additionally, the pwMS were screened for symptoms of anxiety and depression. The patients were divided into two groups based on their self-reported adherence to prescribed and/or non-prescribed medication. These groups were compared regarding psychometric, sociodemographic, clinical, medication, and vaccination-related data.

A subset of the pwMS (19.9%, n = 79) stated that they skip or miss a medication at least once a month. On average, these patients were significantly younger, had lower disability scores and a lower disease severity than the adherent pwMS. The non-adherent patients also had significantly lower scores for self-directedness and compassion as well as higher scores for shyness, self-forgetfulness and anxiety. A higher proportion of non-adherent than adherent pwMS were diagnosed with depression (24.1% vs. 14.5%). Dimethyl fumarate and interferon beta-1b were prescribed over two times more frequently in the non-adherent pwMS group.

This study shows that personality traits are related to medication use in pwMS. Together with clinical-demographic factors, they contributed to the prediction of non-adherence in exploratory multivariable analyses. Individual patient characteristics should therefore be considered in the identification of pwMS who may have difficulties adhering to their treatment. This would facilitate targeted discussions about concerns such as side effects and the provision of support to improve medication management.