Apathy is associated with increased amyloid burden in mild cognitive impairment

Apathy is the most common neuropsychiatric symptom in mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia. The authors sought to determine whether apathy is associated with cortical amyloid burden, as measured by Pittsburgh Compound B (PiB) positron emission tomography (PET), and regional hypometabolism, measured by 18F-fluorodeoxyglocuse (FDG) PET in MCI. The authors found a significant association between increased apathy (lower Apathy Evaluation Scale score) and greater cortical PiB retention independent of age, but no significant association between apathy and regional FDG metabolism. These results suggest that increased apathy is associated with greater amyloid burden but not regional hypometabolism in MCI.