“…The prevalence of DD remains high but has improved 6 – 15 ( Table 1 ). Predisposing factors include healthcare system barriers, 5 , 15 comorbidities, 16 , 17 primary progressive MS, 7 , 9 , 11 , 12 , 18 , 19 and lower education, 7 , 19 but the exact determinants in individual patients are often unclear. Furthermore, the relationship between diagnostic and DMT delays, and disease activity is not well described.…”