The association between caregiver cognitive status and potentially harmful caregiver behavior was assessed in a sample of 180 caregiver-care recipient dyads. Compromised cognitive status was identified in 39% of these informal caregivers. Beyond variance explained by demographic factors, amount of care provided, care recipient cognitive status, and caregiver depressed affect, care recipients reported more frequently being subjected to potentially harmful caregiver behavior when their caregivers evidenced compromised cognitive status. While preliminary, critical areas of caregiver cognition appeared to be deficits in language comprehension and memory. Results indicate that compromised cognitive status is common among informal caregivers of impaired elders and that this may adversely influence the quality of care they provide.

The manner in which executive control functioning exerts its influence on functional tasks was investigated. Sixty older adults were administered neuropsychological tasks tapping into four domains of executive control function, including working memory, planning, fluency, and flexibility. A test of performance-based functional ability also was administered. Correlational analyses demonstrated that working memory was most strongly associated with performance-based functional ability; however, impairment in planning appeared to best predict performance-based functional decrement in simultaneous regression models. Results highlight the role of planning in the maintenance of functional ability, as measured by performance-based functional measures.

Vitamin B12 status has been linked to cognitive impairment among older adults. Deficit in methylmalonic acid (MMA) may be reflective of cognitive impairment because it is a biochemically sensitive marker of B12 deficiency. In a cross-sectional study the contributions of different indices of B12 status, including serum B12, MMA and total homocysteine (tHcy), were measured in relation to cognitive functioning. B12 deficiency as measured by elevated MMA concentrations appeared to be most reflective of cognitive impairment and appeared to contribute unique variance to cognitive measures after controlling for other biochemical variables. Demographic variables, particularly education and age, were more strongly associated with cognitive measures than was MMA. Monitoring and reducing serum MMA concentrations by increasing the intake of vitamin B12 may provide protection against cognitive decline in this and other older populations.