时间标签：数据日期 2026-10-31 · 生成时间 2026-11-01 05:30（Asia/Shanghai）｜ 检索窗口 PubMed edat 2026/10/28–2026/10/31 ｜ 情报发生日期 2026-10-31
研究问题
However, we currently lack a strong understanding of the mechanisms that might explain this risk, particularly the underlying neurobiology.；However, this framework is not universally accepted, and its application to social isolation and loneliness research remains limited.；To date, there are currently three systematic reviews that have synthesized the literature on this topic, with numerous of the included studies examining younger adult samples., , However, Lam et al.’s review focused only on loneliness, Xiong et al. only explored social isolation, and Zovetti et al. included loneliness studies when exploring the neural basis of social isolation.
方法
Participants with cognitive impairment, dementia (including Alzheimer's disease), or depression (including major depressive disorder) were eligible for inclusion.；We excluded participants with other clinical diagnoses or conditions.；These eligibility criteria were selected to capture evidence across the cognitive‐health continuum relevant to dementia, including cognitively unimpaired populations, cognitive impairment, and dementia.；For studies that included both cognitively healthy participants and participants with cognitive impairment, dementia, or depression, results were eligible only if they were analyzed and reported separately for each group.
核心结论
Upon assessment, 41 studies were deemed to overall have low risk of bias, and 1 study was considered to have moderate risk; see Supplementary Material.；However, the majority of studies revealed moderate risk of bias within the results domain, particularly regarding not accounting for non‐response bias or response rates.；Additionally, a few studies exhibited moderate risk of bias for their methodologies, specifically not justifying same sizes, not using valid/reliable measures for exposure variables, not addressing/categorizing non‐responders, and incomplete follow‐up (for cohort studies). ‖ 结论：This systematic review synthesized the existing literature exploring the underlying neurobiological associations of both social isolation and loneliness in middle–older adult populations, highlighting the shared and exclusive neural correlates.
局限
As the studies differed in the GM regions examined and analytic approaches used, these patterns should be interpreted as trends within the existing literature rather than definitive neurobiological distinctions.；Furthermore, these findings are limited by substantial methodological heterogeneity evident across three key domains, operationalization of social isolation and loneliness, neurobiological outcomes, and statistical reporting, which will be discussed.；However, as the majority of these studies used cross‐sectional designs (7/9), these findings should be interpreted with caution as temporal relationships cannot be established.
对本项目的价值
★★☆☆☆ 脑老化是最大未满足需求，也是终点最难量化的领域；biomarker 与认知读数选择最敏感。
全文来源
PMC JATS 全文（正文 59,648 字符，已过标题/DOI 逐字归属校验）
原文题录
- 英文标题：The underlying neurobiology of social isolation and loneliness in middle-older adults: A systematic review.
- 期刊与标识：Alzheimers Dement · PMID 42948906 · DOI 10.1002/alz.71921
C 级证据分级：C 级（预印本 / 观点评论，非原始研究）
本文属观点/评论类文献，不是原始研究。其论点依赖于作者对既有证据的梳理与判断，不构成新的实验证据。本站标注 C 级即为此意——阅读时请把它当作「领域内的思考框架」，而非「研究发现」。
关于本文的文献来源：本站依据 IMA 知识库「五刊监控·深度文献卡片」撰写，依据已获取的期刊全文（方法、样本量与结论已回到原文核对）；未能获取全文的同批条目另行标注「摘要级」，全程未做任何数值推算补全。