Furthermore, we had the opportunity to further explore the association of multimorbidity measures with AD‐related plasma biomarkers in a subsample, which showed that the presence of multimorbidity and the number of chronic conditions were associated with increased plasma Aβ42 and NfL, indicating that amyloid and neurodegeneration might partly underline the association of multimorbidity load with dementia. Here, NEFL is linked to Alzheimer disease.