Associations among mild behavioral impairment, cognition, and brain pathology in preclinical autosomal dominant Alzheimer's disease
Abstract INTRODUCTION The Mild Behavioral Impairment Checklist (MBI‐C) captures neuropsychiatric symptoms in individuals at risk of dementia. In this study, we examined MBI‐C scores in autosomal dominant Alzheimer's disease (ADAD). METHODS We included 83 cognitively unimpaired presenilin‐1 E280A mutation carriers and 114 non‐carriers with MBI‐C, obfjective cognition, and subjective cognitive decline (SCD) assessments. Study sub‐samples underwent neuroimaging to assess Alzheimer's disease (AD) pathology and neurodegeneration. RESULTS MBI‐C total scores were greater in carriers than non‐carriers (r rb = 0.19 [95% confidence interval (CI) 0.05, 0.31], P = 0.009), driven by impulse dyscontrol symptoms. Elevated MBI‐C scores were associated with higher study partner–reported SCD scores (β = 0.28 [95% CI 0.07, 0.050], P = 0.008) and with greater neocortical amyloid beta (β = 0.46 [95% CI 0.17, 0.075], P = 0.003) among carriers. DISCUSSION Our study reveals that mild behavioral impairment symptoms may emerge before cognitive decline in ADAD and supports the MBI‐C as a tool for detecting early behavioral changes linked to AD pathology and identifying at‐risk individuals for clinical trials and early intervention.