White Matter Alterations Associated with Pro-inflammatory Cytokines in Patients with Major Depressive Disorder

Objective@#Regarding the neuroinflammatory theory of major depressive disorder (MDD), little is known about the effect of pro-inflammatory cytokines on white matter (WM) changes in MDD. We aimed to investigate the relationship between pro-inflammatory cytokines and WM alterations in patients with MDD. @*Methods@#Twenty-two patients with MDD and 22 healthy controls (HC) were evaluated for brain imaging and pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, interferon-γ and tumor necrosis factor (TNF)-α. Tract-based spatial statistics and FreeSurfer were used for brain image analysis. @*Results@#The levels of TNF-αand IL-8 were significantly higher in the MDD group than in HC. Compared to HC, lower fractional anisotropy (FA), and higher median diffusivity (MD) and radial diffusivity (RD) values were found in the MDD group for several WM regions. Voxel-wise correlation analysis showed that the level of TNF-α was negatively correlated with FA, and positively correlated with MD and RD in the left body and genu of the corpus callosum, left anterior corona radiata, and left superior corona radiata. @*Conclusion@#Our findings suggest that TNF-α may play an important role in the WM alterations in depression, possibly through demyelination.

White Matter Alterations Associated with Pro-inflammatory Cytokines in Patients with Major Depressive Disorder

Objective@#Regarding the neuroinflammatory theory of major depressive disorder (MDD), little is known about the effect of pro-inflammatory cytokines on white matter (WM) changes in MDD. We aimed to investigate the relationship between pro-inflammatory cytokines and WM alterations in patients with MDD. @*Methods@#Twenty-two patients with MDD and 22 healthy controls (HC) were evaluated for brain imaging and pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, interferon-γ and tumor necrosis factor (TNF)-α. Tract-based spatial statistics and FreeSurfer were used for brain image analysis. @*Results@#The levels of TNF-αand IL-8 were significantly higher in the MDD group than in HC. Compared to HC, lower fractional anisotropy (FA), and higher median diffusivity (MD) and radial diffusivity (RD) values were found in the MDD group for several WM regions. Voxel-wise correlation analysis showed that the level of TNF-α was negatively correlated with FA, and positively correlated with MD and RD in the left body and genu of the corpus callosum, left anterior corona radiata, and left superior corona radiata. @*Conclusion@#Our findings suggest that TNF-α may play an important role in the WM alterations in depression, possibly through demyelination.

Erratum: Effects of Uric Acid on the Alterations of White Matter Connectivity in Patients with Major Depression

The authors discovered that the p-value for group difference in sex (male/female) in Table 1 was incorrect. And the authors described unclearly whether the p-value for the sex distribution was obtained by chi-square test or Fisher's exact test.

Effects of Uric Acid on the Alterations of White Matter Connectivity in Patients with Major Depression

OBJECTIVE: Uric acid is a non-enzymatic antioxidant associated with depression. Despite its known protective role in other brain disorders, little is known about its influence on the structural characteristics of brains of patients with major depressive disorder (MDD). This study explored the association between uric acid and characteristics of white matter (WM) in patients with MDD. METHODS: A total of 32 patients with MDD and 23 healthy controls (HCs) were examined. All participants were scored based on the Beck Depression Inventory and Beck Anxiety Inventory at baseline. All patients were also rated with the Hamilton Depression Rating Scale. We collected blood samples from all participants immediately after their enrollment and before the initiation of antidepressants in case of patients. Tract-based spatial statistics were used for all imaging analyses. RESULTS: Lower fractional anisotropy (FA) and higher radial diffusivity (RD) values were found in the MDD group than in the HC group. Voxelwise correlation analysis revealed that the serum uric acid levels positively correlated with the FA and negatively with the RD in WM regions that previously showed significant group differences in the MDD group. The correlated areas were located in the left anterior corona radiata, left frontal lobe WM, and left anterior cingulate cortex WM. CONCLUSION: The present study suggests a significant association between altered WM connectivity and serum uric acid levels in patients with MDD, possibly through demyelination.

Association of Plasma Levels of Angiotensin-Converting Enzyme and Cytokines with Recurrent Depression : A Preliminary Study

OBJECTIVES: Angiotensin-converting enzyme (ACE) gene and plasma levels of cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), have previously been determined to be associated with depression. The purpose of this study was to investigate the association of plasma levels of ACE and cytokines with recurrent depression. METHODS: A total of 52 participants (14 male, 38 female, aged 43.9 ± 14.0 years) were enrolled after being diagnosed with depression by experienced psychiatrists using the Mini International Neuropsychiatric Interview from the outpatient clinic of the Department of Psychiatry, CHA Bundang Medical Center. The participants completed blood sampling, the Hamilton Depression Rating Scale (HAMD), the Beck Depression Inventory, the Beck Anxiety Inventory, and the Scale for Suicidal Ideation. RESULTS: ACE plasma levels are higher in patients with recurrent depression (27.4 ± 10.4 U/L) than in patients with newly diagnosed depression (19.1 ± 7.7 U/L) (p = 0.004). The levels of cytokines, such as TNF-α, IL-4, IL-6, IL-10, are not significantly different between the two groups. Additionally, the ACE plasma level is negatively correlated with a reduction in the HAMD over six weeks (r = −0.429, p = 0.046, n = 22). CONCLUSIONS: The current findings show that plasma ACE levels may be associated with recurrent depression and further suggest that the renin-angiotensin system could play a role in recurrent depression.