Decreased working memory and processing speed mediate cognitive impairment in geriatric depression
Decreased working memory and processing speed mediate cognitive impairment in geriatric depression
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DOI：
10.1017/s0033291799001968
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发表时间：
2000-05-01
影响因子：
6.9
通讯作者：
Reynolds, CF
中科院分区：
文献类型：
--
作者：
Nebes, RD;Butters, MA;Reynolds, CF
背景虽然神经心理功能障碍在老年抑郁症中很常见，但并非所有认知方面都受到同样的影响。有人认为，抑郁症患者受损的任务，使大量的处理资源的需求，因此，资源递减的神经心理递减老年抑郁症。本研究探讨是否加工资源的形式，工作记忆和信息处理速度下降，抑郁症，以及是否在这些资源的减少实际上介导的神经心理损伤。处理资源的措施，管理老年抑郁症患者治疗前和年龄匹配的控制。抑郁症缓解的患者和对照组一样被重新测试。受试者还接受了情景记忆和视觉空间表现的神经心理学测试。抑郁症患者在处理速度和工作记忆方面的表现明显更差。虽然抑郁症缓解的患者在这些指标上的表现有所改善，但改善的程度并不大于重复测试的对照组。分层回归分析表明，抑郁症解释了显着量的变异的神经心理任务。然而，如果首先去除与加工资源相关的方差，抑郁不再是神经心理学方差的重要组成部分。老年抑郁症患者的处理资源减少，这种资源的减少似乎介导了神经心理功能的几个领域，包括情景记忆和视觉空间表现的损害。抑郁症缓解后，资源减少持续存在，因此可能是老年抑郁症的一个特质标记。
Background. While neuropsychological dysfunction is common in geriatric depression, not all aspects of cognition are equally affected. It has been suggested that depressed patients are impaired only in tasks that make heavy demands on processing resources and that a resource decrement therefore underlies the neuropsychological decrements seen in geriatric depression. The present study examined whether processing resources in the form of working memory and information processing speed are decreased in depression and whether a decrease in these resources actually mediates neuropsychological impairment.Methods. Measures of processing resources were administered to elderly depressed patients prior to treatment and to age-matched controls. Patients whose depression remitted were retested as were the controls. Subjects also received neuropsychological tests of episodic memory and visuospatial performance.Results. Depressed patients performed significantly worse on measures of both processing speed and working memory. While performance on these measures improved in patients whose depression remitted, the amount of improvement was no greater than that seen in the controls with repeat testing. Hierarchical regression analyses showed that depression explained a significant amount of variance on the neuropsychological tasks. However, if the variance associated with processing resources was removed first, depression no longer accounted for a significant amount of neuropsychological variance.Conclusions. Processing resources are decreased in elderly depressed patients and this decrease in resources appears to mediate impairments in several areas of neuropsychological functioning including episodic memory and visuospatial performance. The resource decrement persists after remission of the depression and thus may be a trait marker of geriatric depression.