Study the frequency of mild behavioral impairment (MBI) and its association with mild cognitive impairment (MCI) in participants of the Mayo Clinic Study of Aging (MCSA).

Mild behavioral impairment (MBI) is a construct developed to detect persons at increased dementia risk and refers to a new onset of neuropsychiatric symptoms (NPS) at ≥ 50 years old that persists for≥ 6 months.

Cross-sectional study in the population-based MCSA setting, including participants aged ≥ 50 years, without dementia at MCSA baseline, with at least one follow-up visit, and available Neuropsychiatric Inventory Questionnaire (NPI-Q), neuropsychological testing, and cognitive diagnosis data. MBI was categorized into three categories using data from the MCSA baseline and first follow-up visits. Based on previous research, a participant had MBI if, at both visits, at least one NPS on the NPI-Q was present. If only one of these two visits had an NPS, then they were classified as NPS. Otherwise, a person was classified as “noNPS”(reference); we modified the MBI definition to match the 15-month interval between MCSA evaluation visits. Linear and logistic regression models were adjusted for age, sex, and education.

The study comprised 3882 participants [mean age (standard deviation): 74.80 (9.43); 47.1% were female].  10.8% of participants had MBI, and 19.7% had NPS.  Having MBI and having NPS were associated with higher MCI odds (OR=4.48, 95%CI 3.40, 5.59 and OR=3.05, 95%CI 2.40, 3.89 respectively; vs. noNPS) in the total sample without dementia, and in cognitively unimpaired participants at MCSA baseline (MBI: OR=2.76, 95%CI 1.78, 4.17; NPS: OR=2.37, 95%CI 1.67, 3.35; vs. noNPS).  Findings related to the outcomes of global and domain-specific z-scores agreed.

Having MBI was associated with increased odds of having MCI, also suggesting a potential dose-response association between the MBI/NPS categories and MCI. Longitudinal studies are warranted.