Mild Behavioral Impairment as a Predictor of Functional Status

Area of Science:

• Neurology
• Gerontology
• Neuropsychiatry

Background:

• Mild behavioral impairment (MBI) is recognized in older adults but its impact on daily functioning, independent of dementia, remains understudied.
• Specific behavioral markers within MBI may predict functional decline in cognitively normal (CN) and mild cognitive impairment (MCI) individuals.

Purpose of the Study:

• To investigate the relationship between specific MBI behavioral markers and functional decline in CN and MCI.
• To assess if individuals with MBI exhibit worse cognition and neurodegenerative changes compared to those without MBI.

Main Methods:

• Cross-sectional observational study using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database.
• Included 232 amnesic MCI (aMCI) and 418 cognitively normal (CN) participants.
• Utilized neuropsychological assessments, MRI, Flortaucipir PET scans, Functional Assessment Questionnaire (FAQ), and neuropsychiatric inventory.

Main Results:

• MBI was present in 53.5% of aMCI and 19.6% of CN participants.
• In aMCI, affective dysregulation, impulse dyscontrol, and decreased drive were most common; in CN, affective dysregulation and impulse dyscontrol predominated.
• MBI domains (affective dysregulation, decreased drive, social inappropriateness, abnormal perception) predicted FAQ scores in aMCI, while only decreased drive predicted FAQ in CN. MBI did not affect tau deposition or brain volumes.

Conclusions:

• MBI occurrence predicts a high risk of daily life dysfunction in both MCI and CN individuals.
• Early identification of functional impairment associated with MBI may enhance the effectiveness of disease-modifying interventions.