Depression and Anxiety in Association with Polypharmacy in Patients with Multiple Sclerosis

Polypharmacy (intake of ≥5 drugs) is an important issue for patients with chronic diseases such as multiple sclerosis (MS). We aimed to assess the prevalence of polypharmacy with regard to the severity of anxiety/depression and to comorbidities. Therefore, 374 MS patients from two German neurological sites were examined for drug burden, comorbidities, disability level and psychopathological measures capturing depression and anxiety using the Hospital Anxiety and Depression Scale (HADS-A and HADS-D). We found that patients with a higher HADS-D score take more medication (r = 0.217, p < 0.001). Furthermore, patients with higher depression severity were more likely to show polypharmacy (p < 0.001). These differences were not significant for anxiety. (p = 0.413). Regarding the frequency of ≥1 comorbidities, there were no significant differences between patients with different HADS-A (p = 0.375) or HADS-D (p = 0.860) severity levels, whereas the concrete number of comorbidities showed a significant positive linear correlation with HADS-A (r = 0.10, p = 0.045) and HADS-D scores (r = 0.19, p < 0.001). In conclusion, symptoms of depression pose a relevant issue for MS patients and are correlated with polypharmacy and comorbidities. Anxiety is not correlated with polypharmacy but with the frequency of several comorbidity groups in MS patients.