Browsing by Author "Chen, Yao-Liang"

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Cognitive Reserve Moderates Effects of White Matter Hyperintensity on Depressive Symptoms and Cognitive Function in Late-Life Depression
(2020-04-08)
Lin, Chemin
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Huang, Chih-Mao
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Fan, Yang-Teng
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Liu, Ho-Ling
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Chen, Yao-Liang
Introduction White matter hyperintensity (WMH) has been regarded as one of the major contributor of the vascular hypothesis of late-life depression (LLD) and cognitive decline in the elderly. On the other hand, cognitive reserve (CR) has long been hypothesized to provide resilience and adaptability against age- and disease-related insults. This study examined the role of CR, using proxy of education, in moderating the association between WMH and clinical LLD expression. Methods A total of 54 elderly diagnosed with major depressive disorder and 38 matched healthy controls participated in this study. They received MRI scanning and a battery of neuropsychological tests. WMH was quantified by an automated segmentation algorithm. Linear regression analyses were conducted separately in the LLD and control groups to examine the effects of WMH, education and their interaction in depression severity and various cognitive domains. Results WMH was significantly and negatively associated with executive function only in the healthy controls. In patients with LLD, we observed a significant interactive effect in education on the association between WMH and depression severity and language domain (category fluency task). Specifically, those with high education showed less depressive symptoms and cognitive decline as WMH increased. Conclusion WMH is associated with lower cognitive function. However, in patients with LLD, high education attenuates the deleterious effect of WMH on mood and cognition. Therefore, CR appears to exert a protective effect on neurocognitive functioning in people with LLD.
Cognitive reserve-mediated neural modulation of emotional control and regulation in people with late-life depression
(2019-08-01)
Huang, Chih-Mao
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Fan, Yang-Teng
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Lee, Shwu-Hua
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Liu, Ho-Ling
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Chen, Yao-Liang
Late-life depression (LLD) is an affective disorder that is highly prevalent among older people. Cognitive reserve (CR) refers to an active process that facilitates the flexibility and efficiency of the neural networks to compensate for impairments that emerge in consequence of brain pathology. The current functional magnetic resonance imaging study investigated whether and how CR affects emotional regulation, level of depression severity and neural activity associated with affective control during emotional Stroop (eStroop) task. Altogether, 90 older people participated in this study, 50 of whom suffered from LLD. We used years of education and verbal fluency capacity as proxies for CR. Clinical participants with relatively higher CR presented with milder degrees of depression, better eStroop performance and stronger neural activity in the middle frontal gyrus (MFG) involved with exercising affective control. Results of the mediation analysis indicated that both education and verbal fluency significantly mediated the association between the depression severity and MEG activity. These results suggest a negative association between CR and age-related clinical symptoms of emotional dysregulation. Our neurobehavioral findings provide supportive evidence that CR implies efficiency of top-down emotional regulation and operates as a protective factor against emotional and cognitive vulnerability in the aging brain.
Increased brain entropy of resting-state fMRI mediates the relationship between depression severity and mental health-related quality of life in late-life depressed elderly
(2019-05-01)
Lin, Chemin
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Lee, Shwu-Hua
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Huang, Chih-Mao
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Chen, Guan-Yen
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Ho, Pei-Shan
Background: Entropy analysis is a computational method used to quantify the complexity in a system, and loss of brain complexity is hypothesized to be related to mental disorders. Here, we applied entropy analysis to the resting-state functional magnetic resonance imaging (rs-fMRI) signal in subjects with late-life depression (LLD), an illness combined with emotion dysregulation and aging effect. Methods: A total of 35 unremitted depressed elderly and 22 control subjects were recruited. Multiscale entropy (MSE) analysis was performed in the entire brain, 90 automated anatomical labeling-parcellated ROIs, and five resting networks in each study participant. Limitations: Due to ethical concerns, all the participants were under medication during the study. Results: Regionally, subjects with LLD showed decreased entropy only in the right posterior cingulate gyrus but had universally increased entropy in affective processing (putamen and thalamus), sensory, motor, and temporal nodes across different time scales. We also found higher entropy in the left frontoparietal network (FPN), which partially mediated the negative correlation between depression severity and mental components of the quality of life, reflecting the possible neural compensation during depression treatment. Conclusion: MSE provides a novel and complementary approach in rs-fMRI analysis. The temporal-spatial complexity in the resting brain may provide the adaptive variability beneficial for the elderly with depression.
The relationship between loneliness and working-memory-related frontoparietal network connectivity in people with major depressive disorder
(2020-09-01)
Gao, Mengxia
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Shao, Robin
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Huang, Chih-Mao
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Liu, Ho-Ling
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Chen, Yao-Liang
Loneliness affects up to 40 % of middle-aged and older adults, and is closely associated with major depressive disorder (MDD). However, the relationship between loneliness and neural network functioning during executive cognitive processes, such as working memory, in MDD is still unclear. To address this gap, our study recruited 21 medicated MDD patients (mean age = 52.0 +/- 5 years) and 24 matched healthy controls (HC) (mean age = 48.7 +/- 6 years) who completed an n-back fMRI task. For behavioural performance, we observed no significant moderating effect of MDD or loneliness on the task condition effect. However, loneliness was positively associated, and MDD was negatively associated, with the functional connectivity between the inferior parietal cortex and the rostral dorsomedial prefrontal cortex (DMPFC) during task performance. Furthermore, an interactive effect of loneliness and MDD was observed on the functional connectivity between the supplementary motor area and the caudal DMPFC during the n-back task, with loneliness showing a positive relationship in the HC group but a negative relationship in the MDD group with the connectivity. Our results indicated that loneliness may be associated with altered neural regulatory functioning on self-referential processing and action control, which may further depend on the individual's depressive state. These findings can form the theoretical basis for devising intervention programme aimed at improving the mental wellness of the healthy and depressed lonely individuals.
The relationships between brain structural changes and perceived loneliness in older adults suffering from late-life depression
(2018-04-01)
Sin, Emily L. L.
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Liu, Ho-Ling
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Lee, Shwu-Hua
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Huang, Chih-Mao
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Wai, Yau-Yau
ObjectiveLate-life depression is a significant health risk factor for older adults, part of which is perceived loneliness. In this voxel-based morphometry study, we examined the relationships between perceived loneliness and depression recurrence. MethodsFifty-two older adults were recruited, and they were split into 3 groups: single episode, multiple episodes, or normal control groups, according to their clinical histories. ResultsThis result suggests the level of functioning regarding the reward system may be negatively related to the number of depressive episodes. Taken together, the findings of this study offer important insight into the neural underpinnings of the course and chronicity of late-life depression.