Ravdin L D, Katzen H L, Agrawal P, Relkin N R
Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
Clin Neuropsychol. 2003 May;17(2):195-202. doi: 10.1076/clin.17.2.195.16500.
Depression induced cognitive impairment, also referred to as the dementia syndrome of depression or pseudodementia, has been well characterized, yet the extent to which the more common mild depressive symptoms influence cognition has not been well studied. We sought to identify the influence of mild depressive symptoms on verbal fluency performance in a large sample of healthy community dwelling older adults. Letter and semantic fluency testing was conducted on 188 participants (ages 60-92 years) with no known history of neurologic or psychiatric disease. Depressive symptoms were assessed with the Geriatric Depression Scale (GDS). A total of 39 subjects obtained GDS scores consistent with mild depressive symptoms (GDS=10-19), and 149 subjects were identified as not depressed (GDS<10). ANOVA indicated that subjects with mild depressive symptoms performed significantly worse than normal controls on letter fluency (p<.05), but there was no significant difference between the groups on semantic fluency. Analysis of the nondepressed group stratified into young-old, middle-old, and oldest-old revealed a significant decline in semantic (p<.001) but not letter fluency with age. The nondepressed young-old showed the expected advantage for word list generation to semantic as compared to letter categories, yet this pattern was reversed in the older age groups, where letter fluency scores exceeded semantic fluency scores. Our results suggest that the presence of even mild depressive symptoms may confound using letter versus category discrepancies in the differential diagnosis of dementia. Further, our findings suggest that the commonly used strategy of examining letter-semantic fluency discrepancies may not be relevant for individuals of advanced age. Age-stratified normative data for fluency testing in older adults is also provided.
抑郁症所致认知障碍，也被称为抑郁性痴呆综合征或假性痴呆，其特征已得到充分描述，但更为常见的轻度抑郁症状对认知的影响程度尚未得到充分研究。我们试图在大量居住于社区的健康老年人样本中确定轻度抑郁症状对言语流畅性表现的影响。对188名（年龄在60 - 92岁之间）无已知神经或精神疾病史的参与者进行了字母和语义流畅性测试。使用老年抑郁量表（GDS）评估抑郁症状。共有39名受试者的GDS得分符合轻度抑郁症状（GDS = 10 - 19），149名受试者被确定为无抑郁（GDS < 10）。方差分析表明，有轻度抑郁症状的受试者在字母流畅性方面的表现显著差于正常对照组（p <.05），但两组在语义流畅性方面无显著差异。对非抑郁组按年轻老人、中年老人和高龄老人进行分层分析发现，随着年龄增长，语义流畅性有显著下降（p <.001），但字母流畅性无显著下降。非抑郁的年轻老人在生成语义相关单词列表方面比生成字母相关单词列表表现出预期优势，但在老年组中这种模式相反，字母流畅性得分超过了语义流畅性得分。我们的结果表明，即使是轻度抑郁症状的存在也可能在痴呆的鉴别诊断中混淆使用字母与类别差异。此外，我们的研究结果表明，常用的检查字母 - 语义流畅性差异的策略可能与高龄个体无关。还提供了老年人流畅性测试的年龄分层规范数据。
