Introduction: Reduced speed of information processing seems to characterize neuropsychological performance in multiple sclerosis (MS) patients. However, the impact in speed of information processing of depressive symptoms, that are highly prevalent in this population, has not been precisely defined yet due to the presence of some methodological limitations in most preceding studies.
Subjects and methods: 42 MS remittent recurrent patients, 20 with depressive symptoms (BDI > 13), and 22 without, were compared to 24 healthy controls in neuropsychological tasks of speed of processing (SDMT, Stroop, TMT y PASAT-BNB).
Results: MS patients without depressive symptoms performed significantly worse than healthy controls the Stroop (W, C and WC), and the PASAT-BNB (execution time) tests. MS patients with depressive symptoms performed significantly worse than healthy controls the Stroop (W, C and WC), SDMT, TMT (A, B and B-A), and the PASAT-BNB (execution time and errors) tests. MS patients with depressive symptoms performed significantly worse than MS patients without depressive symptoms the SDMT, TMT (A, B and B-A), and the PASAT-BNB (execution time) tests.
Conclusions: MS impact was not generalized in neuropsychological performance of patients. Depressive symptoms seem to play and important role determining the speed deficit. While MS reduced speed of information processing, depressive symptoms were associated to specific cognitive deficit different from speed ones.