Relating the CDR‐SB, a global measure of AD dementia severity used in clinical trials, to independence in IADLs and BADLs can help patients and their families understand the benefit of treatment. The course of AD dementia from symptom onset to death generally occurs over 7–10 years, 31 making the effects of treatment more difficult to understand when trials occur over a relatively short period (18 months). The issue of how long to treat with DMTs remains unresolved. It is very difficult to know whether treatment effects will persist past the clinical trial period, although it has been noted that the treatment effect of lecanemab seemed to increase with duration of treatment. 1
