Brain network correlates of affective symptoms in aMCI

Affective symptoms (i.e., depression, anxiety, and apathy) are the most prevalent subsyndrome of neuropsychiatric symptoms (NPS) in preclinical dementia, such as amnestic mild cognitive impairment (aMCI), and remain a challenge to understand and treat. The distressing nature of these symptoms and complexity of their concurrence and interaction necessitates improved understanding of their underlying neural correlates. We analyzed the relationships between functional brain topology (i.e., the way the brain's functional network is organized to allow efficient communication between regions) and affective symptoms in aMCI using cross-sectional and longitudinal methods. The analyses demonstrated that increased clustering coefficient (CC) was related to lower baseline and greater decreases in affective symptoms, while higher participation coefficient (PC) was correlated with more severe baseline affective symptoms. These findings suggest that the brain losing the capacity to form segregated functional units may be related to prevalence and severity of affective symptoms seen in aMCI.