The neurobiology of depression in later-life: clinical, neuropsychological, neuroimaging and pathophysiological features

As the population ages, the economic and societal impacts of neurodegenerative and neuropsychiatric disorders are expected to rise sharply. Like dementia, late-life depressive disorders are common and are linked to increased disability, high healthcare utilisation, cognitive decline and premature mortality. Considerable heterogeneity in the clinical presentation of major depression across the life cycle may reflect unique pathophysiological pathways to illness; differentiating those with earlier onset who have grown older (early-onset depression), from those with illness onset after the age of 50 or 60 years (late-onset depression). The last two decades have witnessed significant advances in our understanding of the neurobiology of early- and late-onset depression, and has shown that disturbances of fronto-subcortical functioning are implicated. New biomedical models extend well beyond perturbations of traditional monoamine systems to include altered neurotrophins, endocrinologic and immunologic system dysfunction, inflammatory processes and gene expression alterations. This more recent research has highlighted that a range of illness-specific, neurodegenerative and vascular factors appear to contribute to the various phenotypic presentations. This review highlights the major features of late-life depression, with specific reference to its associated aetiological, clinical, cognitive, neuroimaging, neuropathological, inflammatory and genetic correlates. Data examining the efficacy of pharmacological, non-pharmacological and novel treatments for depression are discussed. Ultimately, future research must aim to evaluate whether basic biomedical knowledge can be successfully translated into enhanced health outcomes via the implementation of early intervention paradigms.     

显微CT对下颌活髓第一磨牙疑难牙根纵裂的诊断价值

目的评价显微CT（MCT）对下颌活髓第一磨牙疑难牙根纵裂的诊断价值。方法对本院牙片未能诊断、经MCT确诊的疑难牙根纵裂的下颌活髓第一磨牙56颗患牙的病史、临床表现等进行回顾性分析。并按MCT所显示纵裂根形态、患牙牙根总数、纵裂位置及纵裂根根管数对患牙进行统计分析。结果56颗疑难患牙中绝大多数仅有轻中度松动、[牙合]面磨耗和牙周炎的症状;54颗（93.1%）下颌第一磨牙所有近中根均为双根管扁根,其中42颗（77.8%）除具有上述特征外且只有两个牙根,此类牙发生牙根纵裂有显著统计学差异（P〈0.00）。结论牙根纵裂与慢性咬合创伤、牙周疾病和牙根解剖变异密切相关。