Mild Behavioral Impairment and Subjective Cognitive Decline Predict Cognitive and Functional Decline

Area of Science:

• Neuroscience
• Gerontology
• Dementia Research

Background:

• Mild behavioral impairment (MBI) and subjective cognitive decline (SCD) are recognized dementia risk states.
• Both MBI and SCD are associated with early neurodegeneration and predict future cognitive decline and dementia.
• They are considered Stage 2 (preclinical disease) in the NIA-AA Alzheimer's Disease research framework.

Purpose of the Study:

• To investigate the associations of MBI and SCD, both individually and combined, with incident cognitive and functional decline.
• To test the hypothesis that MBI and SCD confer additive risk for decline in older adults.

Main Methods:

• A cohort of cognitively normal older adults was followed annually at Alzheimer's Disease Centers.
• Logistic regression analysis was used to assess the relationship between baseline MBI and SCD status (alone or combined) and 3-year cognitive/functional decline.
• Participants were categorized into four groups: MBI-SCD-, MBI-SCD+, MBI+SCD-, and MBI+SCD+.

Main Results:

• Out of 2,769 participants, 12.6% experienced decline (CDR >0) within 3 years.
• The risk of decline showed an ordinal progression: MBI-SCD+ (16.5% progression, OR 3.61), MBI+SCD- (20.7% progression, OR 4.76), and MBI+SCD+ (30.9% progression, OR 8.15).
• The combination of MBI and SCD demonstrated the highest risk of decline (30.9% progression).

Conclusions:

• The co-occurrence of Mild Behavioral Impairment and Subjective Cognitive Decline significantly elevates the risk of cognitive and functional decline.
• These syndromes serve as valuable, easily implementable tools for identifying high-risk individuals for further medical evaluation or clinical trial participation.
• MBI and SCD are complementary indicators of preclinical dementia.