Axonal myelin increase in the callosal genu in depression but not schizophrenia

2015 ◽  
Vol 45 (10) ◽  
pp. 2145-2155 ◽  
Author(s):  
M. R. Williams ◽  
P. Sharma ◽  
K. L. Fung ◽  
R. K. B. Pearce ◽  
S. R. Hirsch ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
High Resolution ◽  
Depressive Disorder ◽  
Sagittal Plane ◽  
Brain Regions ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Myelinated Axons ◽  
Major Depressive ◽  
Cross Sectional

BackgroundAbnormalities in the anterior inter-hemispheric connectivity have previously been implicated in major depressive disorder. Disruptions in fractional anisotropy in the callosum and fornix have been reported in schizophrenia and major depressive disorder. Oligodendrocyte density and overall size of the callosum and fornix show no alteration in either illness, suggesting that gross morphology is unchanged but more subtle organizational disruption may exist within these brain regions in mood and affective disorders.MethodUsing high-resolution oil-immersion microscopy we examined the cross-sectional area of the nerve fibre and the axonal myelin sheath, and using standard high-resolution light microscopy we measured the density of myelinated axons. These measurements were made in the genu of the corpus callosum and the medial body of the fornix at its most dorsal point. Measures were taken in the sagittal plane in the callosal genu and in the coronal plane at the most dorsal part of the fornix body.ResultsCases of major depressive disorder had significantly greater mean myelin cross-sectional area (p = 0.017) and myelin thickness (p = 0.004) per axon in the genu than in control or schizophrenia groups. There was no significant change in the density of myelinated axons, and no changes observed in the fornix.ConclusionThe results suggest a clear increase of myelin in the axons of the callosal genu in MDD, although this type of neuropathological study is unable to clarify whether this is caused by changes during life or has a developmental origin.

Effects of genetic variants on neural circuits in major depression

2011 ◽  
Vol 26 (S2) ◽  
pp. 2085-2085
Author(s):  
T. Frodl
Keyword(s):  
Major Depressive Disorder ◽  
High Resolution ◽  
Cognitive Control ◽  
Depressive Disorder ◽  
Early Life ◽  
Brain Regions ◽  
High Angular Resolution ◽  
Major Depressive ◽  
Early Life Adversity ◽  
Brain Changes

IntroductionThe underlying neurobiology of major depressive disorder (MDD) is likely to represent an interaction between genetic susceptibility and environmental factors like stress. There is growing evidence that epigenetic processes might mediate the effects of the social environment during childhood on gene expression.ObjectivesWe investigated in multimodal high-resolution MRI-genetic studies whether microstructural and functional brain changes are the result of gene-environment interactions.MethodsPatients with major depressive disorder (MDD), high-risk subjects for developing MDD and healthy participants were investigated using high-resolution magnetic resonance imaging (MRI), high angular resolution diffusion imaging (HARDI) and functional MRI. Furthermore, we assessed early life adversity and measured the serotonin transporter polymorphisms (5-HTTLPR).ResultsWe demonstrated that patients with MDD have smaller hippocampal and frontal cortex volumes associated with gen-environment interactions. Healthy Subjects at risk for developing depression, who manage to stay healthy, show better activation of the frontal cognitive control system. Those who had stronger fibre connections between frontal and temporal brain regions also better managed incidences of adversity in early life.ConclusionsStress x gene interactions seem to account for at least some of the structural brain changes. Resilience against environmental stressors might be associated with stronger neural fibre connections and more effective cognitive control networks.

scholarly journals Cortical structural differences in major depressive disorder correlate with cell type-specific transcriptional signatures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiao Li ◽  
Jakob Seidlitz ◽  
John Suckling ◽  
Feiyang Fan ◽  
Gong-Jun Ji ◽  
...  
Keyword(s):  
Gene Expression ◽  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Structural Changes ◽  
Brain Regions ◽  
Cell Type ◽  
Major Depressive ◽  
Structural Differences ◽  
Neuroimaging Data ◽  
Cell Type Specific

AbstractMajor depressive disorder (MDD) has been shown to be associated with structural abnormalities in a variety of spatially diverse brain regions. However, the correlation between brain structural changes in MDD and gene expression is unclear. Here, we examine the link between brain-wide gene expression and morphometric changes in individuals with MDD, using neuroimaging data from two independent cohorts and a publicly available transcriptomic dataset. Morphometric similarity network (MSN) analysis shows replicable cortical structural differences in individuals with MDD compared to control subjects. Using human brain gene expression data, we observe that the expression of MDD-associated genes spatially correlates with MSN differences. Analysis of cell type-specific signature genes suggests that microglia and neuronal specific transcriptional changes account for most of the observed correlation with MDD-specific MSN differences. Collectively, our findings link molecular and structural changes relevant for MDD.

Optical Coherence Tomography and Pattern Electroretinography Changes in Egyptian Patients with Major Depressive Disorder

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Mostafa S ElShaarawi ◽  
Ayman A Gaafar ◽  
Hisham S. Saad Eldin ◽  
Randa H Ali
Keyword(s):  
Optical Coherence Tomography ◽  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Control Group ◽  
Ophthalmological Examination ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Major Depressive ◽  
Cross Sectional ◽  
Pattern Electroretinography

Abstract Background Major depressive disorder (MDD) is a common psychiatric disorder that affects nearly 11.1-14.6 % of the population in their lifetime. Pathophysiology and brain imaging findings show that degenerative and inflammatory processes may play a role. Meta-analysis of voxel-based morphometry studies in MDD demonstrated significant gray matter loss. From anatomical and embryological perspectives, the retina can be considered a unique extension of the brain and is able to reflect axonal histopathology. Being unmyelinated, it can provide insight into the pathophysiological processes of diseases with a neurodegenerative element. Aim to compare retinal optical coherence tomography (OCT) parameters in a group of MDD patients with a healthy control group and to correlate OCT parameters with pattern electroretinography (PERG) parameters. Method a controlled cross sectional study was conducted on 30 MDD patients and 28 age and sex matched controls. Both groups had a full ophthalmological examination, OCT imaging and 7 patients and 11 controls have PERG recorded. Results Thinning of the superior retinal nerve fiber layer, thinning of most of the ganglion cell inner plexiform (GCIP) layer, thinning of most of the macular thickness and thinning of macular volume in both eyes were detected. There was a statistically significant positive correlation between the left GCIP layer and the amplitude of the N95 wave. Also a statistically significant negative correlation existed between MDD duration in years with the left eye's average volume of the outer ring of the macula. Conclusion Significant retinal changes were detected by OCT in MDD patients supporting the theory of neurodegeneration as a pathophysiology of MDD.

scholarly journals Previous disorders and depression outcomes in individuals with 12-month major depressive disorder in the World Mental Health surveys

2021 ◽  
Vol 30 ◽  
Author(s):  
Annelieke M. Roest ◽  
Ymkje Anna de Vries ◽  
Ali Al-Hamzawi ◽  
Jordi Alonso ◽  
Olatunde O. Ayinde ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Composite International Diagnostic Interview ◽  
Diagnostic Interview ◽  
Major Depressive ◽  
Cross Sectional ◽  
Epidemiological Surveys ◽  
Externalising Disorders ◽  
Days Out Of Role ◽  
The Impact

Abstract Aims Major depressive disorder (MDD) is characterised by a recurrent course and high comorbidity rates. A lifespan perspective may therefore provide important information regarding health outcomes. The aim of the present study is to examine mental disorders that preceded 12-month MDD diagnosis and the impact of these disorders on depression outcomes. Methods Data came from 29 cross-sectional community epidemiological surveys of adults in 27 countries (n = 80 190). The Composite International Diagnostic Interview (CIDI) was used to assess 12-month MDD and lifetime DSM-IV disorders with onset prior to the respondent's age at interview. Disorders were grouped into depressive distress disorders, non-depressive distress disorders, fear disorders and externalising disorders. Depression outcomes included 12-month suicidality, days out of role and impairment in role functioning. Results Among respondents with 12-month MDD, 94.9% (s.e. = 0.4) had at least one prior disorder (including previous MDD), and 64.6% (s.e. = 0.9) had at least one prior, non-MDD disorder. Previous non-depressive distress, fear and externalising disorders, but not depressive distress disorders, predicted higher impairment (OR = 1.4–1.6) and suicidality (OR = 1.5–2.5), after adjustment for sociodemographic variables. Further adjustment for MDD characteristics weakened, but did not eliminate, these associations. Associations were largely driven by current comorbidities, but both remitted and current externalising disorders predicted suicidality among respondents with 12-month MDD. Conclusions These results illustrate the importance of careful psychiatric history taking regarding current anxiety disorders and lifetime externalising disorders in individuals with MDD.

Altered Brain Network Degree Centrality in Major Depressive Disorder via Electro-Acupuncture Stimulation at Baihui(gv20)

2021 ◽  
Author(s):  
Shasha Li ◽  
Ya Chen ◽  
Gaoxiong Duan ◽  
Yong Pang ◽  
Huimei Liu ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Brain Function ◽  
Brain Regions ◽  
Brain Network ◽  
Degree Centrality ◽  
Major Depressive ◽  
Acupuncture Stimulation ◽  
Therapeutic Mechanisms ◽  
Abnormal Brain

Abstract Background: Although the acupuncture treatment of major depressive disorder(MDD) has been recognized by the latest clinical practice guidelines of the American Academy of Internal Medicine, complex therapeutic mechanisms need further to clarify. The aim of the study is investigate whether the aberrant resting state brain network in MDD patients could be regulated by acupuncture at GV20 using functional magnetic resonance imaging(fMRI) combined with degree centrality(DC) method. Results: Compared to healthy subjects, MDD patients exhibited significantly aberrant DC in widely brain regions, including cortical(PFC, precuneus, temporal, insula) and sub-cortical (thalamus, putamen and caudate) structures. Furthermore, results showed that acupuncture at GV20 induced down-regulation the DC of abnormal brain regions in MDD patients. Conclusions: Our findings provide imaging evidence to support that GV20-related acupuncture stimulation may modulate the abnormal brain function state in MDD patients by using fMRI technique combined with DC analysis. This study may partly interpret the neural mechanisms of acupuncture at GV20 which is used to treat patients with MDD in clinical. Trial registration: ChiCTR, ChiCTR-IOR-15006357. Registered 05 May 2015, http://www.chictr.org.cn/showproj.aspx?proj=10922.

scholarly journals Major depression subtypes are differentially associated with migraine subtype, prevalence and severity

Cephalalgia ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 347-356 ◽  
Author(s):  
Claudia Pisanu ◽  
Emma Lundin ◽  
Martin Preisig ◽  
Mehdi Gholam-Rezaee ◽  
Enrique Castelao ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Migraine With Aura ◽  
Migraine Without Aura ◽  
Population Based ◽  
Cross Sectional Study ◽  
High Rate ◽  
Major Depressive ◽  
Cross Sectional ◽  
Depression Subtypes

Objective Migraine and major depressive disorder show a high rate of comorbidity, but little is known about the associations between the subtypes of major depressive disorder and migraine. In this cross-sectional study we aimed at investigating a) the lifetime associations between the atypical, melancholic, combined and unspecified subtype of major depressive disorder and migraine with and without aura and b) the associations between major depressive disorder and its subtypes and the severity of migraine. Methods A total of 446 subjects with migraine (migraine without aura: n = 294; migraine with aura: n = 152) and 2511 controls from the population-based CoLaus/PsyCoLaus study, Switzerland, were included. Associations between major depressive disorder subtypes and migraine characteristics were tested using binary logistic or linear regression. Results Melancholic, combined and unspecified major depressive disorder were associated with increased frequency of migraine with aura, whereas only melancholic major depressive disorder was associated with increased frequency of migraine without aura. Lifetime and unspecified major depressive disorder were associated with severe migraine intensity among subjects with migraine with aura but not migraine without aura, while combined major depressive disorder was associated with higher migraine frequency independently from migraine subtype. Conclusion This study suggests that melancholic but not atypical major depressive disorder is associated with migraine and migraine subtypes. Future studies exploring pathophysiological mechanisms shared between melancholic depression and migraine are warranted.

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