BACKGROUND: The neuropsychiatric syndrome Mild Behavioral Impairment (MBI) describes
an at-risk state for dementia and may be a useful screening tool for sample enrichment. We
hypothesized that stratifying a cognitively normal sample on MBI status would enhance the
association between genetic risk for Alzheimer’s disease (AD) and ...
BACKGROUND: The neuropsychiatric syndrome Mild Behavioral Impairment (MBI) describes
an at-risk state for dementia and may be a useful screening tool for sample enrichment. We
hypothesized that stratifying a cognitively normal sample on MBI status would enhance the
association between genetic risk for Alzheimer’s disease (AD) and cognition.
METHODS: Data from 4,458 participants over 50 without dementia was analysed. A cognitive
composite score was constructed and the MBI Checklist was used to stratify into those with
MBI and those without. Polygenic scores for AD were generated using summary statistics
from the IGAP study.
RESULTS: AD genetic risk was associated with worse cognition in the MBI group but not in
the no MBI group (MBI: β=-0.09, 95% CI: -0.13 - -0.03, p=0.002, R =0.003). The strongest
association was in those with more severe MBI aged ≥65.
CONCLUSIONS: MBI is an important feature of aging, screening on MBI may be a useful
sample enrichment strategy for clinical research.