Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Feb;22(2):195-206.
doi: 10.1016/j.jagp.2013.03.005. Epub 2013 Jul 3.

Graph theory analysis of cortical-subcortical networks in late-life depression

Olusola Ajilore  1 , Melissa Lamar  2 , Alex Leow  2 , Aifeng Zhang  2 , Shaolin Yang  3 , Anand Kumar  2
Affiliations

Graph theory analysis of cortical-subcortical networks in late-life depression

Olusola Ajilore et al. Am J Geriatr Psychiatry. 2014 Feb.

Abstract

Objectives: Late-life major depression (LLD) is characterized by distinct epidemiologic and psychosocial factors, as well as medical comorbidities that are associated with specific neuroanatomical differences. The purpose of this study was to use interregional correlations of cortical and subcortical volumes to examine cortical-subcortical structural network properties in subjects with LLD compared with healthy comparison subjects.

Methods: This was a cross-sectional neuroimaging study conducted in the general community. We recruited 73 healthy elderly comparison subjects and 53 subjects with LLD who volunteered in response to advertisements. Brain network connectivity measures were generated by correlating regional volumes after controlling for age, gender, and intracranial volume by using the Brain Connectivity Toolbox.

Results: Results for overall network strength revealed that LLD networks showed a greater magnitude of associations for both positive and negative correlation weights compared with healthy elderly networks. LLD networks also demonstrated alterations in brain network structure compared with healthy comparison subjects. LLD networks were also more vulnerable to targeted attacks compared with healthy elderly comparison subjects, and this vulnerability was attenuated when controlling for white matter alterations.

Conclusions: Overall, this study demonstrates that cortical-subcortical network properties are altered in LLD and may reflect the underlying neuroanatomical vulnerabilities of the disorder.

Keywords: Connectivity; depression; geriatric; network analysis; neuroimaging.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Interregional volume correlation matrices.
Figure 2
Figure 2
Correlation strength. The late-life depressed correlations matrix had overall significantly higher positive strengths (t = −26, df = 5500, p < .0001) and significantly more negative strengths (t = 4.25, df = 485, p < .0001). Error bars represent one standard deviation.
Figure 3
Figure 3
Global network metrics. A. Gamma B. Lambda C. Sigma D. Global Efficiency. Significance was established if the absolute difference between groups was greater than 95% of the differences observed in 1000 resampled groups (p < .05).
Figure 3
Figure 3
Global network metrics. A. Gamma B. Lambda C. Sigma D. Global Efficiency. Significance was established if the absolute difference between groups was greater than 95% of the differences observed in 1000 resampled groups (p < .05).
Figure 4
Figure 4
Hub differences. Coronal view of a transparent brain with hubs that are stronger in healthy comparison subjects indicated in red, while stronger hubs in late-life depressed subjects are in blue
Figure 5
Figure 5
Network resilience. A. Random Failure Analysis B. Targeted Failure Analysis C. Targeted Failure Analysis controlling for white matter hypointensities (WMH). Significance was established if the absolute difference between groups was greater than 95% of the differences observed in 1000 resampled groups (p < .05).
Figure 5
Figure 5
Network resilience. A. Random Failure Analysis B. Targeted Failure Analysis C. Targeted Failure Analysis controlling for white matter hypointensities (WMH). Significance was established if the absolute difference between groups was greater than 95% of the differences observed in 1000 resampled groups (p < .05).
See this image and copyright information in PMC

References

    1. Alexopoulos GS. Depression in the elderly. Lancet. 2005;365 (9475):1961–1970. - PubMed
    1. Alexopoulos GS, Kiosses DN, Choi SJ, et al. Frontal white matter microstructure and treatment response of late-life depression: a preliminary study. Am J Psychiatry. 2002;159 (11):1929–1932. - PubMed
    1. Bai F, Shu N, Yuan Y, et al. Topologically Convergent and Divergent Structural Connectivity Patterns between Patients with Remitted Geriatric Depression and Amnestic Mild Cognitive Impairment. J Neurosci. 2012;32 (12):4307–4318. - PMC - PubMed
    1. Bassett DS, Bullmore E, Verchinski BA, et al. Hierarchical organization of human cortical networks in health and schizophrenia. J Neurosci. 2008;28 (37):9239–9248. - PMC - PubMed
    1. Beck AT, Steer RA, Brown GK. Manual for the Beck Depression Inventory-II. San Antonio, TX: The Psychological Corporation; 1996.

Publication types

LinkOut - more resources