Dataset Information

Amygdala network dysfunction in late-life depression phenotypes: Relationships with symptom dimensions.

ABSTRACT: The amygdala, a crucial hub of the emotional processing neural system, has been implicated in late-life depression (LLD) pathophysiology. However, the overlapping and diverging amygdala network function abnormalities underlying two clinical LLD phenotypes (i.e., LLD alone and LLD with mild cognitive impairment [LLD-MCI]) are unknown. The aim of this study is to investigate the amygdala functional connectivity (FC) differences between LLD alone, LLD-MCI and healthy controls, and to examine the relationships between amygdala network dysfunction and symptom dimensions. A resting-state functional connectivity magnetic resonance imaging study was conducted to probe amygdala FC in a total of 63 elderly participants (LLD [n = 22], LLD-MCI [n = 15], and age- and gender-equated healthy older adults [n = 26]) using a seed-based voxelwise R-fcMRI approach. LLD-only adults showed increased FC in the posterior default mode and vermis, and diminished connections in the fronto-parietal, salience and temporal areas, relative to controls. The LLD-MCI participants showed diminished FC in the default mode, cognitive control, salience and visual regions, whereas increased FC was limited to lateral parietal cortex compared with healthy controls. The LLD-MCI group also showed diminished FC in the occipital and posterior default mode areas, relative to the LLD-only group. Distinct amygdala FC abnormalities that explain depressive and anxiety symptom severity, and executive functioning were identified. The amygdala FC impairments may distinguish LLD phenotypes. These functional network abnormalities may also explain the heterogeneity seen in the LLD clinical presentations.

SUBMITTER: Li W

PROVIDER: S-EPMC4605880 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature

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Amygdala network dysfunction in late-life depression phenotypes: Relationships with symptom dimensions.

Li Wenjun W Ward B Douglas BD Xie Chunming C Jones Jennifer L JL Antuono Piero G PG Li Shi-Jiang SJ Goveas Joseph S JS

Journal of psychiatric research 20150909

The amygdala, a crucial hub of the emotional processing neural system, has been implicated in late-life depression (LLD) pathophysiology. However, the overlapping and diverging amygdala network function abnormalities underlying two clinical LLD phenotypes (i.e., LLD alone and LLD with mild cognitive impairment [LLD-MCI]) are unknown. The aim of this study is to investigate the amygdala functional connectivity (FC) differences between LLD alone, LLD-MCI and healthy controls, and to examine the re ...[more]

PMID: 26424431

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Project description:Background: Depression and anxiety are the most common comorbid psychiatric disorders in the elderly. Psychiatrists have been reporting worsened depression symptoms and prognosis by comorbid anxiety symptoms. However, it is still unclear how anxiety affects the course of depression in the elderly. The aims of this study are (1) to identify the symptom network in late-life depression (LLD), and (2) to examine the role of anxiety in LLD with a network perspective. Methods: The study analyzed 776 community-based participants who were clinically diagnosed with depression and enrolled in Suwon Geriatric Mental Health Center. Network analysis was used to investigate the relationships between the symptoms of the Montgomery-Åsberg Depression Rating Scale (MADRS). The depression sample was divided into groups of low and high anxiety according to the Beck Anxiety Index. Propensity score matching (PSM) was used to minimize the effects of depression severity on the network. Network comparison test (NCT) were carried out to compare the global connectivity, global strength, and specific edge strength between the two subgroups. Results: Reported sadness, pessimistic thinking, and suicidal ideation are the core symptoms of LLD in terms of node strength. The MADRS sum score [mean (SD) 28.10 (9.19) vs 20.08 (7.11); P < .01] was much higher in the high anxiety group. The NCT before PSM showed the high anxiety group had significantly higher global strength (P < .01). However, the NCT after PSM did not reveal any statistical significance both in global structure (P = .46) and global strength (P = .26). A comparison between centrality indices showed a higher node strength of vegetative symptoms in the high anxiety group and this also remained after PSM. Conclusion: Based on the statistical analysis, anxiety worsens the severity of depression in the elderly. However, NCT after PSM revealed comorbid anxiety does not change the global structure and strength of the depression symptom network. Therefore, anxiety may affect LLD in a way of worsening the severity, rather than changing psychopathology. Additionally, the study revealed the centrality of vegetative symptoms was low in LLD but increased substantially in patients with comorbid anxiety.

Project description:ImportanceKnowledge gaps persist regarding racial and ethnic variation in late-life depression, including differences in specific depressive symptoms and disparities in care.ObjectiveTo examine racial/ethnic differences in depression severity, symptom burden, and care.Design, setting, and participantsThis cross-sectional study included 25 503 of 25 871 community-dwelling older adults who participated in the Vitamin D and Omega-3 Trial (VITAL), a randomized trial of cancer and cardiovascular disease prevention conducted from November 2011 to December 2017. Data analysis was conducted from June to September 2018.ExposureRacial/ethnic group (ie, non-Hispanic white; black; Hispanic; Asian; and other, multiple, or unspecified race).Main outcomes and measuresDepressive symptoms, assessed using the Patient Health Questionnaire-8 (PHQ-8); participant-reported diagnosis, medication, and/or counseling for depression. Differences across racial/ethnic groups were evaluated using multivariable zero-inflated negative binomial regression to compare PHQ-8 scores and multivariable logistic regression to estimate odds of item-level symptom burden and odds of depression treatment among those with diagnosed depression.ResultsThere were 25 503 VITAL participants with adequate depression data (mean [SD] age, 67.1 [7.1] years) including 12 888 [50.5%] women, 17 828 [69.9%] non-Hispanic white participants, 5004 [19.6%] black participants, 1001 [3.9%] Hispanic participants, 377 [1.5%] Asian participants, and 1293 participants [5.1%] who were categorized in the other, multiple, or unspecified race group. After adjustment for sociodemographic, lifestyle, and health confounders, black participants had a 10% higher severity level of PHQ-8 scores compared with non-Hispanic white participants (rate ratio [RR], 1.10; 95% CI, 1.04-1.17; P < .001); Hispanic participants had a 23% higher severity level of PHQ-8 scores compared with non-Hispanic white participants (RR, 1.23; 95% CI, 1.10-1.38; P < .001); and participants in the other, multiple, or unspecified group had a 14% higher severity level of PHQ-8 scores compared with non-Hispanic white participants (RR, 1.14; 95% CI, 1.04-1.25; P = .007). Compared with non-Hispanic white participants, participants belonging to minority groups had 1.5-fold to 2-fold significantly higher fully adjusted odds of anhedonia (among black participants: odds ratio [OR], 1.76; 95% CI, 1.47-2.11; among Hispanic participants: OR, 1.96; 95% CI, 1.43-2.69), sadness (among black participants: OR, 1.31; 95% CI, 1.07-1.60; among Hispanic participants: OR, 2.09; 95% CI, 1.51-2.88), and psychomotor symptoms (among black participants: OR, 1.77; 95% CI, 1.31-2.39; among Hispanic participants: OR, 2.12; 95% CI, 1.28-3.50); multivariable-adjusted odds of sleep problems and guilt appeared higher among Hispanic vs non-Hispanic white participants (sleep: OR, 1.24; 95% CI, 1.01-1.52; guilt: 1.84; 95% CI, 1.31-2.59). Among those with clinically significant depressive symptoms (ie, PHQ-8 score ≥10) and/or those with diagnosed depression, black participants were 61% less likely to report any treatment (ie, medications and/or counseling) than non-Hispanic white participants after adjusting for confounders (adjusted OR, 0.39; 95% CI, 0.27-0.56).Conclusions and relevanceIn this cross-sectional study, significant racial and ethnic differences in late-life depression severity, item-level symptom burden, and depression care were observed after adjustment for numerous confounders. These findings suggest a need for further examination of novel patient-level and clinician-level factors underlying these associations.

Project description:Late-life depression (LLD) and amnestic mild cognitive impairment (aMCI) are associated with medial temporal lobe structural abnormalities. However, the hippocampal functional connectivity (HFC) similarities and differences related to these syndromes when they occur alone or coexist are unclear. Resting-state functional connectivity MRI (R-fMRI) technique was used to measure left and right HFC in 72 elderly participants (LLD [n = 18], aMCI [n = 17], LLD with comorbid aMCI [n = 12], and healthy controls [n = 25]). The main and interactive relationships of LLD and aMCI on the HFC networks were determined, after controlling for age, gender, education and gray matter volumes. The effects of depressive symptoms and episodic memory deficits on the hippocampal functional connections also were assessed. While increased and decreased left and right HFC with several cortical and subcortical structures involved in mood regulation were related to LLD, aMCI was associated with globally diminished connectivity. Significant LLD-aMCI interactions on the right HFC networks were seen in the brain regions critical for emotion processing and higher-order cognitive functions. In the interactive brain regions, LLD and aMCI were associated with diminished hippocampal functional connections, whereas the comorbid group demonstrated enhanced connectivity. Main and interactive effects of depressive symptoms and episodic memory performance were also associated with bilateral HFC network abnormalities. In conclusion, these findings indicate that discrete hippocampal functional network abnormalities are associated with LLD and aMCI when they occur alone. However, when these conditions coexist, more pronounced vulnerabilities of the hippocampal networks occur, which may be a marker of disease severity and impending cognitive decline. By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.

Dataset Information

Amygdala network dysfunction in late-life depression phenotypes: Relationships with symptom dimensions.

Publications

Amygdala network dysfunction in late-life depression phenotypes: Relationships with symptom dimensions.

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