Wei Xu1, Wei Feng2, Xue-Ning Shen3, Yan-Lin Bi4, Ya-Hui Ma1, Jie-Qiong Li5, Qiang Dong3, Lan Tan1, Jin-Tai Yu6. 1. Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China. 2. Department of Psychological Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. 3. Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China. 4. Department of Anesthesiology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China. 5. Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China. 6. Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China. Electronic address: jintai_yu@fudan.edu.cn.
Abstract
BACKGROUND: The relationship between depression and Alzheimer's disease (AD) is complex and still not well understood. We aimed to examine the roles of the AD core pathologies in modulating the associations of minimal depressive symptoms (MDSs) with cognitive impairments. METHODS: A total of 721 participants who had measures of cognition, depressive symptoms, and cerebrospinal fluid AD biomarkers were included from the CABLE (Chinese Alzheimer's Biomarker and LifestylE) study. Causal mediation analyses with 10,000 bootstrapped iterations were conducted to explore the mediation effects of AD pathologies on cognition. The ADNI (Alzheimer's Disease Neuroimaging Initiative) was used 1) to replicate the mediation effects and 2) to examine the longitudinal relationships of MDSs with amyloid pathology and incident AD risk. RESULTS: In CABLE, MDSs were associated with poorer global cognition (p = .006) and higher amyloid burden as indicated by cerebrospinal fluid amyloid markers (p < .0001). The influence of MDSs on cognition was partially mediated by amyloid pathology (a maximum of 85%). The mediation effects were replicated in 725 elderly persons without dementia (age, mean ± SD = 73.5 ± 6.9 years; 301 female subjects [42%]) in ADNI, such that the mediation percentage varied from 10% to 30% for general cognition, memory, and executive functions. Longitudinal analyses revealed a bidirectional relationship between MDSs and amyloid pathology (p = .01). MDSs were associated with 83% increased risk of developing AD dementia (hazard ratio = 1.83, p < .01). CONCLUSIONS: Overall, amyloid pathology might partially mediate and magnify the influences of MDSs on cognitive impairments and AD risk.
BACKGROUND: The relationship between depression and Alzheimer's disease (AD) is complex and still not well understood. We aimed to examine the roles of the AD core pathologies in modulating the associations of minimal depressive symptoms (MDSs) with cognitive impairments. METHODS: A total of 721 participants who had measures of cognition, depressive symptoms, and cerebrospinal fluid AD biomarkers were included from the CABLE (Chinese Alzheimer's Biomarker and LifestylE) study. Causal mediation analyses with 10,000 bootstrapped iterations were conducted to explore the mediation effects of AD pathologies on cognition. The ADNI (Alzheimer's Disease Neuroimaging Initiative) was used 1) to replicate the mediation effects and 2) to examine the longitudinal relationships of MDSs with amyloid pathology and incident AD risk. RESULTS: In CABLE, MDSs were associated with poorer global cognition (p = .006) and higher amyloid burden as indicated by cerebrospinal fluid amyloid markers (p < .0001). The influence of MDSs on cognition was partially mediated by amyloid pathology (a maximum of 85%). The mediation effects were replicated in 725 elderly persons without dementia (age, mean ± SD = 73.5 ± 6.9 years; 301 female subjects [42%]) in ADNI, such that the mediation percentage varied from 10% to 30% for general cognition, memory, and executive functions. Longitudinal analyses revealed a bidirectional relationship between MDSs and amyloid pathology (p = .01). MDSs were associated with 83% increased risk of developing AD dementia (hazard ratio = 1.83, p < .01). CONCLUSIONS: Overall, amyloid pathology might partially mediate and magnify the influences of MDSs on cognitive impairments and AD risk.