Distractibility in multiple sclerosis: The role of depression

The present study assesses the influence of depression and anxiety on the effects of cognitive distracters in people with multiple sclerosis (MS). Participants completed computerized versions of the Symbol Digit Modalities Test (c-SDMT) with (n = 51) and without (n = 51) auditory distracters. Based on the Hospital Anxiety and Depression Scale (HADS), 29 (28.4%) and 51 (50%) participants were classified as depressed or anxious, respectively. A regression analysis revealed that depression (p = 0.034), not anxiety (p = 0.264), further impaired performance on the c-SDMT, particularly in the presence of distracters. These results suggest that distracter effects are influenced by depression more than anxiety. Given that distracters are ubiquitous in real-world environments, their use in a cognitive assessment adds to the ecological validity of the results.