To test whether adherence to treatment in patients with MS is influenced by cognitive variables (executive functions), personality, and social support.

This is a pilot observational, descriptive, cross-sectional study. 60 patients with Relapsing remitting MS ( 73.33% female; age: 41.41 ±14.00) undergoing medical treatment ( 28 dymethilfumarate, 7 ocrelizumab/ rituximab, 6 fingolimod, 5 interferon, 5 natalizumab, 4 cladribine, 3 teriflunomide, 1 alemtuzumab, 1 glatiramer acetate) underwent a comprehensive multi-component evaluation including : cognition, social support (using the self-reported record of social support scale), personality (using the NEO-FFI questionnaire) and evaluation of treatment adherence using the Morisky Green Levine Medication Adherence Scale Participants were divided into two groups according to their adherence to medical treatment, low vs. high adherence was defined using a cutoff score of 4. Differences between groups were evaluated using Student's t-test with a significance level of p<0.05, the effect size was calculated with Cohen's d test.

Groups did not differ significantly in age, sex, type of treatment, Montreal Cognitive Assesments (MoCA) or neuropsychiatric scales of depression and anxiety. Regardless of treatment type, 63.33% of the patients had high treatment adherence. Significant differences between groups were found in the Global Index of Social Support (p=0.016, Cohen's d= 0.73) and the responsibility factor of the NEO-FFI (p=0.048, Cohen's d= 0.20). Conversely, no significant differences were found in executive functions (p=0.8), Openness (p=0.062), Extraversion (p=0.5), Neuroticism (p=0.4) and Agreeableness (p=0.8).

Social support and the responsibility factor of personality are significantly different between MS patients with high and low adherence to medical treatment. The study of social support and personality may be a key component in improving adherence strategies.