Phenotyping of mild behavioral impairment domains in multi-regional dementia-free older adults of Chinese ethnicity: impulse dyscontrol as the leading domain

BACKGROUND: Mild behavioral impairment (MBI) is an early neurobehavioral marker of dementia, yet MBI domain patterns remain underexplored among populations of Chinese ethnicity. This study aimed to characterize MBI domain phenotypes by examining the prevalence of MBI domains and identifying the leading domain across multi-regional cohorts of dementia-free older adults of Chinese ethnicity. METHODS: Data from three previously unpublished datasets (Hangzhou community cohort, China Longitudinal Aging Study and Singapore memory clinic cohort) and three published studies were integrated to estimate the MBI domain prevalence, measured by the Neuropsychiatric Inventory (NPI) and/or MBI-Checklist (MBI-C), through a random-effects meta-analysis. Within the Hangzhou cohort, cross-instrument consistency was evaluated. Exploratory analyses were performed in the Singapore cohort on associations between MBI domains and incident dementia. RESULTS: Among 1817 participants, impulse dyscontrol was the most prevalent MBI domain, followed by affective dysregulation and decreased motivation, consistently across instruments and cognitive status. In the exploratory longitudinal analyses, impulse dyscontrol was associated with a greater likelihood of incident dementia (HR = 5.05, 95%CI = 2.92 - 8.73). CONCLUSIONS: Impulse dyscontrol was the leading MBI domain among older adults of Chinese ethnicity, with potential clinical relevance for early identification and dementia risk stratification.