Study Report
Reference
| Citation | Horn, 2010 PubMed |
| Full Info | Horn, D.I., Yu, C., Steiner, J., Buchmann, J., Kaufmann, J., Osoba, A., Eckert, U., Zierhut, K.C., Schiltz, K., He, H. et al. (2010) Glutamatergic and resting-state functional connectivity correlates of severity in major depression - the role of pregenual anterior cingulate cortex and anterior insula. Front Syst Neurosci, 4.
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Study
| Hypothesis or Background |
Glutamatergic mechanisms and resting-state functional connectivity alterations have been recently described as factors contributing to major depressive disorder (MDD). Furthermore, the pregenual anterior cingulate cortex (pgACC) seems to play an important role for major depressive symptoms such as anhedonia and impaired emotion processing.
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| Sample Information | 22 MDD patients and 22 healthy subjects. Severity of depression was rated using the 21-item Hamilton depression scale (HAMD) and patients were divided into severely and mildly depressed subgroups according to HAMD scores. All patients were medicated using SSRI, NRI, and SNRI alone or with new generation antidepressants including agomelatine or lithium |
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| Method Detail | We investigated 22 MDD patients and 22 healthy subjects using a combined magnetic resonance spectroscopy (MRS) and resting-state functional magnetic resonance imaging (fMRI) approach. Severity of depression was rated using the 21-item Hamilton depression scale (HAMD) and patients were divided into severely and mildly depressed subgroups according to HAMD scores. Because of their hypothesized role in depression we investigated the functional connectivity between pgACC and left anterior insular cortex (AI). |
| Method Keywords | functional magnetic resonance imaging (fMRI); spectrophotometric analysis; psychometric method |
| Result | The sum of Glutamate and Glutamine (Glx) in the pgACC, but not in left AI, predicted the resting-state functional connectivity between the two regions exclusively in depressed patients. Furthermore, functional connectivity between these regions was significantly altered in the subgroup of severely depressed patients (HAMD > 15) compared to healthy subjects and mildly depressed patients. Similarly the Glx ratios, relative to Creatine, in the pgACC were lowest in severely depressed patients. |
| Conclusions | These findings support the involvement of glutamatergic mechanisms in severe MDD which are related to the functional connectivity between pgACC and AI and depression severity. |
Relationships reported by
Horn, 2010
| Component A Approved Name (Name in Paper) |
Component A Type |
Component B Approved Name (Name in Paper) |
Component B Type |
Statistical Result |
Relationship Description |
Result Category (Positive/Negative)) |
|
MDD
|
syndrome |
Insular cortex (left anterior insular cortex) |
brain morphology and function |
|
Functional connectivity between pgACC and left anterior insular cortex was significantly altered in the subgroup of severely depressed patients compared to healthy subjects and mildly depressed patients. |
Positive
|
|
MDD
|
syndrome |
pregenual anterior cingulate cortex (pregenual anterior cingulate cortex (pgACC)) |
brain morphology and function |
|
Functional connectivity between pgACC and left anterior insular cortex was significantly altered in the subgroup of severely depressed patients compared to healthy subjects and mildly depressed patients. |
Positive
|
|
MDD
|
syndrome |
Glutamatergic system (glutamatergic system) |
neurobiological system |
|
These findings support the involvement of glutamatergic mechanisms in severe MDD which are related to the functional connectivity between pgACC and AI and depression severity. |
Positive
|
|
Insular cortex (left anterior insular cortex)
|
brain morphology and function |
pregenual anterior cingulate cortex (pregenual anterior cingulate cortex (pgACC)) |
brain morphology and function |
|
Functional connectivity between pgACC and left anterior insular cortex was significantly altered in the subgroup of severely depressed patients compared to healthy subjects and mildly depressed patients. |
Positive
|
|
MDD
|
syndrome |
Creatine (creatine) |
molecule |
|
Creatine in the pgACC were lowest in severely depressed patients. |
Positive
|
|
MDD
|
syndrome |
Glutamates (glutamate) |
molecule |
|
the sum of Glutamate in the pgACC predicted the resting-state functional connectivity between the two regions exclusively in depressed patients. |
Positive
|
|
MDD
|
syndrome |
Glutamine (glutamine) |
molecule |
|
The sum of Glutamine (Glx) in the pgACC predicted the resting-state functional connectivity between the two regions exclusively in depressed patients. |
Positive
|
