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Altered Amygdala Connectivity in Individuals with Chronic Traumatic Brain Injury and Comorbid Depressive Symptoms

View Article: PubMed Central

ABSTRACT

Depression is one of the most common psychiatric conditions in individuals with chronic traumatic brain injury (TBI). Though depression has detrimental effects in TBI and network dysfunction is a “hallmark” of TBI and depression, there have not been any prior investigations of connectivity-based neuroimaging biomarkers for comorbid depression in TBI. We utilized resting-state functional magnetic resonance imaging to identify altered amygdala connectivity in individuals with chronic TBI (8 years post-injury on average) exhibiting comorbid depressive symptoms (N = 31), relative to chronic TBI individuals having minimal depressive symptoms (N = 23). Connectivity analysis of these participant sub-groups revealed that the TBI-plus-depressive symptoms group showed relative increases in amygdala connectivity primarily in the regions that are part of the salience, somatomotor, dorsal attention, and visual networks (pvoxel < 0.01, pcluster < 0.025). Relative increases in amygdala connectivity in the TBI-plus-depressive symptoms group were also observed within areas of the limbic–cortical mood-regulating circuit (the left dorsomedial and right dorsolateral prefrontal cortices and thalamus) and the brainstem. Further analysis revealed that spatially dissociable patterns of correlation between amygdala connectivity and symptom severity according to subtypes (Cognitive and Affective) of depressive symptoms (pvoxel < 0.01, pcluster < 0.025). Taken together, these results suggest that amygdala connectivity may be a potentially effective neuroimaging biomarker for comorbid depressive symptoms in chronic TBI.

No MeSH data available.


Observed power for group differences in amygdala connectivity.
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Figure 8: Observed power for group differences in amygdala connectivity.

Mentions: The power analyses demonstrated that our findings have sufficiently reached both statistical significance and statistical power (Figures 7 and 8). The effect size maps for group differences in amygdala connectivity (Figure 7) revealed that the patterns of voxels whose group differences in amygdala connectivity accounted for more than 10% of total variance were similar to those of statistical significance at pvoxel < 0.01 and pcluster < 0.025 (Figure 1). Again, the patterns of observed power values at >0.8 for group comparisons of left and right amygdala connectivity (Figure 8) were similar to those of statistical significance at pvoxel < 0.01 and pcluster < 0.025 (Figure 1).


Altered Amygdala Connectivity in Individuals with Chronic Traumatic Brain Injury and Comorbid Depressive Symptoms
Observed power for group differences in amygdala connectivity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631949&req=5

Figure 8: Observed power for group differences in amygdala connectivity.
Mentions: The power analyses demonstrated that our findings have sufficiently reached both statistical significance and statistical power (Figures 7 and 8). The effect size maps for group differences in amygdala connectivity (Figure 7) revealed that the patterns of voxels whose group differences in amygdala connectivity accounted for more than 10% of total variance were similar to those of statistical significance at pvoxel < 0.01 and pcluster < 0.025 (Figure 1). Again, the patterns of observed power values at >0.8 for group comparisons of left and right amygdala connectivity (Figure 8) were similar to those of statistical significance at pvoxel < 0.01 and pcluster < 0.025 (Figure 1).

View Article: PubMed Central

ABSTRACT

Depression is one of the most common psychiatric conditions in individuals with chronic traumatic brain injury (TBI). Though depression has detrimental effects in TBI and network dysfunction is a &ldquo;hallmark&rdquo; of TBI and depression, there have not been any prior investigations of connectivity-based neuroimaging biomarkers for comorbid depression in TBI. We utilized resting-state functional magnetic resonance imaging to identify altered amygdala connectivity in individuals with chronic TBI (8&thinsp;years post-injury on average) exhibiting comorbid depressive symptoms (N&thinsp;=&thinsp;31), relative to chronic TBI individuals having minimal depressive symptoms (N&thinsp;=&thinsp;23). Connectivity analysis of these participant sub-groups revealed that the TBI-plus-depressive symptoms group showed relative increases in amygdala connectivity primarily in the regions that are part of the salience, somatomotor, dorsal attention, and visual networks (pvoxel&thinsp;&lt;&thinsp;0.01, pcluster&thinsp;&lt;&thinsp;0.025). Relative increases in amygdala connectivity in the TBI-plus-depressive symptoms group were also observed within areas of the limbic&ndash;cortical mood-regulating circuit (the left dorsomedial and right dorsolateral prefrontal cortices and thalamus) and the brainstem. Further analysis revealed that spatially dissociable patterns of correlation between amygdala connectivity and symptom severity according to subtypes (Cognitive and Affective) of depressive symptoms (pvoxel&thinsp;&lt;&thinsp;0.01, pcluster&thinsp;&lt;&thinsp;0.025). Taken together, these results suggest that amygdala connectivity may be a potentially effective neuroimaging biomarker for comorbid depressive symptoms in chronic TBI.

No MeSH data available.