目的:调查与未抑郁的认知未受损(CU)老年人相比,晚期抑郁症(LLD)的tau积累是否更高。通过评估LLD之间tau和灰质体积(GMV)的组差异,在LLD的神经变性模型中定位这些发现,非抑郁CU和阿尔茨海默病(MCI)引起的轻度认知障碍。
方法:单中心,横断面研究。
方法:大学精神病医院,记忆诊所和门诊神经病学实践。
方法:共有102名60岁以上的成年人,其中19名目前患有LLD的抑郁参与者,19名MCI患者和36名非抑郁CU参与者完成了神经心理学测试和tauPET-MR成像。
方法:PET-MRI:用于tau评估的18F-MK-6240示踪剂SUVR;七个脑区的3DT1加权结构MRI衍生的GMV(时间,扣带回,前额叶和顶叶区域);淀粉样蛋白PET评估淀粉样蛋白阳性;神经心理学测试评分:MMSE,RAVLT,GDS,夫人.ANCOVA和Spearman的等级相关性研究tau和GMV的群体差异,并分别与神经心理学测验成绩相关。
结果:与非抑郁CU参与者相比,LLD患者的颞区和前扣带回区GMV较低,但tau积累和淀粉样蛋白阳性率相似。相比之下,MCI患者在所有地区都有显著较高的tau积累。Tau与LLD中的任何神经心理学测试得分均不相关。
结论:我们的研究结果表明,与非抑郁症患者相比,AD型tau在LLD中并不高,认知未受损的老年人,似乎不太可能导致LLD中灰质体积降低,进一步强调需要区分重度抑郁障碍和早期AD发生的抑郁症状。
OBJECTIVE: To investigate whether tau accumulation is higher in late life depression (LLD) compared to non-depressed cognitively unimpaired (CU) older adults. To situate these findings in the neurodegeneration model of LLD by assessing group differences in tau and grey matter volume (GMV) between LLD, non-depressed CU and mild cognitive impairment due to Alzheimer\'s Disease (MCI).
METHODS: Monocentric, cross-sectional study.
METHODS: University Psychiatric hospital, memory clinic and outpatient neurology practice.
METHODS: A total of 102 adults over age 60, of whom 19 currently depressed participants with LLD, 19 with MCI and 36 non-depressed CU participants completed neuropsychological testing and tau PET-MR imaging.
METHODS: PET-MRI: 18F-MK-6240 tracer SUVR for tau assessment; 3D T1-weighted structural MRI derived GMV in seven brain regions (temporal, cingulate, prefrontal and parietal regions); amyloid PET to assess amyloid positivity; Neuropsychological test scores: MMSE, RAVLT, GDS, MADRS. ANCOVA and Spearman\'s rank correlations to investigate group differences in tau and GMV, and correlations with neuropsychological test scores respectively.
RESULTS: Compared to non-depressed CU participants, LLD patients showed lower GMV in temporal and anterior cingulate regions but similar tau accumulation and amyloid positivity rate. In contrast, MCI patients had significantly higher tau accumulation in all regions. Tau did not correlate with any neuropsychological test scores in LLD.
CONCLUSIONS: Our findings suggest AD-type tau is not higher in LLD compared to non-depressed, cognitively unimpaired older adults and appears unlikely to contribute to lower gray matter volume in LLD, further underscoring the need to distinguish major depressive disorder from depressive symptoms occurring in early AD.