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Introduction: It is important to study apathy in Alzheimer's disease (AD) to better understand its underlying neurobiology and develop effective interventions. In the current study, we sought to examine the relationships between longitudinal apathy and regional tau burden in cognitively impaired older adults from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Methods: Three hundred and nineteen ADNI participants with mild cognitive impairment (MCI) or AD dementia underwent flortaucipir (FTP) tau positron emission tomography (PET) imaging and clinical assessment with the Neuropsychiatric Inventory (NPI) annually. Longitudinal NPI Apathy (NPI-A) scores were examined in relation to baseline tau PET signal in three a priori selected regions implicated in AD and AD-related apathy (supramarginal gyrus, entorhinal cortex [EC] and rostral anterior cingulate cortex [rACC]). Secondary models were adjusted for global cognition (Mini-Mental State Examination score) and cortical amyloid (florbetapir PET). Results: Higher baseline supramarginal gyrus and EC tau burden were each significantly associated with greater NPI-A over time, while rACC tau was associated with higher NPI-A but did not predict its trajectory over time. These results were retained for supramarginal and EC tau after adjusting models for global cognition and cortical amyloid. Discussion: Our findings suggest that baseline in vivo tau burden in parietal and temporal brain regions affected in AD, and less so in a medial frontal region involved in motivational control, is associated with increasing apathy over time in older adults with MCI and AD dementia. Future work studying emergent apathy in relation to not only core AD pathology but also circuit level dysfunction may provide additional insight into the neurobiology of apathy in AD and opportunities for intervention. Highlights: Tau (Flortaucipir PET) in regions implicated in AD was associated with increasing apathy over timeCortical amyloid was also found to be a robust predictor of the trajectory of apathyEvidence of synergy between regional tau and amyloid in overall higher levels of apathy.
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Assessing the impact of the COVID-19 pandemic on perceived stress in older adults is critical to understanding how to best support elderly individuals navigating stressful situations, with the aim to lessen the impact of stressors on their brain health. Here, we collected measures on perceived stress, resilience, and behavioral coping strategies, in the context of the COVID-19 pandemic, in a cross-sectional sample of 141 community dwelling older adults (mean age = 74.4 ± 8.4, 59% females) who were part of two longitudinal observational studies in Massachusetts, U.S. Our results indicate that participants demonstrated moderate levels of stress related to COVID-19 and showed relatively high levels of resilience. Higher resilience was associated with greater use of adaptive coping behaviors and less use of maladaptive coping behaviors. The use of maladaptive coping strategies was associated with more stress. Moreover, hierarchical regression analyses revealed that resilience was the strongest unique predictor of stress, thus, largely accounting for the observed coping-outcome associations. Individual differences in resilience levels moderated the effects of two coping strategies (planning and self-blame) on stress. Specifically, planning was associated with increased levels of stress for people with low resilience. In contrast, high personal resilience attenuated the negative effect of self-blame on their stress levels. Taken together, our findings suggest that resilience is critical for coping with stress during the COVID-19 pandemic. Future approaches for augmenting resilience could prove to be important potential interventions to help support older adults navigating stressful situations as well as lessen adverse effects on neurocognitive and mental health in the future.
