OBJECTIVE: To determine whether impulsive traits are more frequent in patients with multiple sclerosis (MS). BACKGROUND: Cognitive dysfunction is present in up to 65[percnt] of patients with MS and is presumably related to demyelination, brain atrophy and other neurodegenerative processes. Behavioral disorders like depression, anxiety, bipolar disorder and psychosis have also been associated with MS. In contrast, less attention has been given to the study of impulsivity in MS. DESIGN/METHODS: 60 patients with MS and 60 age and sex-matched healthy controls were included. All subjects completed the 13-item short form of the Beck Depression Inventory (BDI-SF) and the State-Trait Anxiety Inventory (STAI). Impulsivity was measured using the total score of the Barratt Impulsiveness Scale version 11 (BIS-11) and the percentage of commission errors on the Immediate and Delayed Memory Tasks (IMT-DMT). To test the association of impulsivity and MS, a multiple linear regression model was fitted adjusting for age at enrollment, gender, educational level, BDI-SF score and STAI score. RESULTS: Mean age was 38.2±10 years and 80[percnt] of the subjects were females. EDSS median score was 1.5[interquartile range (IQR) 1-3]. The median BDI-SF score was higher in MS patients ( 5 [IQR 3-10] vs. 1 [IQR 0-3] p<0.001). STAI-Trait score was also higher among patients ( 10 [IQR 2-35] vs. 44 points [IQR 13-72] p=0.0002). Univariate analysis showed a higher BIS-11 total score in MS patients (65.71±10.12 vs 60.85± 11.50, p=0.015), but this difference was not statistically significant in the multivariate analysis. There was no difference between IMT or DMT percentage of commission errors (p= 0.306 and p=0.254, respectively) CONCLUSIONS: Patients with MS showed more depression and trait- anxiety than controls. We did not find differences in the measures of impulsivity between MS patients and healthy controls. Study Supported by: Universidad de los Andes and FSFB