In a chronic disease such as multiple sclerosis (MS), which predominantly affects young adults, it is essential to identify the aspects associated with psychological well-being that impact on functionality and quality of life. Self-determination, defined by the self-perception of autonomy and personal competence, is a factor that influences well-being, motivation and general satisfaction, so its study is essential. 

80 PwMS were included (78% women), Age: 43.81±9.64, Years of education: 14.73±2.98, Years of disease evolution: 11.12±8.41, Clinical phenotype: 67 relapsing remission (84%), 6 secondary-progressive (8%) 5 primary-progressive (6%). The Personal Self-Determination Scale, Fatigue Severity Scale (FSS) and Beck Depression Inventory-II (BDI-II) were administered. For the measurement of cognitive variables, the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) was administered, which includes the following tests: California Verbal Learning Test-I (CVLT-I), Brief Visuospatial Memory Test-Revised (BVMT-R), and Symbol Digit Modalities Test (SDMT). Statistical analysis: To examine the predictors of the level of self-determination, a stepwise linear regression analysis was performed including the variables fatigue, depression, verbal memory, visual memory, processing speed and years of disease evolution as potential predictors. Significance level was accepted at <0.05.

Level of self-determination: 3.66±0.78, BDI-II: 16.30±9.88, FSS: 4.65±3.42. BICAMS: CVLT-I: 48.18±11.16, BVMT-R: 21.94±7.24 and SDMT: 46.19±13.39. Fatigue and depression were significant predictors of self-determination (F=27.12, p<0.001). The final model explained 39.81% of the variability in self-determination (adj R²=0.398). Cognitive variables and years of evolution were excluded from the final model due to their lack of statistical significance.