MK4MDD

Genetic/Epigenetic Locus Search Cross Data Search

Study Report

Reference

Citation	Fingelkurts, 2007 PubMed
Full Info	Fingelkurts, A.A., Rytsala, H., Suominen, K., Isometsa, E. and Kahkonen, S. (2007) Impaired functional connectivity at EEG alpha and theta frequency bands in major depression. Hum Brain Mapp, 28, 247-261.

Study

Hypothesis or Background	Recent reports on functional brain imaging in major depression have lead to an assumption that observed psychopathology might be related to an altered brain functional connectivity. Our hypothesis was that an increase in brain functional connectivity occurs in major depression.
Sample Information	12 medication-free depressive outpatients and 10 control subjects
Method Detail	As a measure of functional connectivity, the electroencephalogram (EEG) structural synchrony approach was used in 12 medication-free depressive outpatients and 10 control subjects. Differences in the number and strength of structurally synchronized EEG patterns were compared between groups.
Method Keywords	electroencephalogram (EEG)
Result	In depressive patients the number and strength of short cortex functional connections were significantly larger for the left than for the right hemisphere, while the number and strength of long functional connections were significantly larger for the right than for the left hemisphere. Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior, posterior, and left hemisphere functional connections for the alpha frequency band and short-range anterior functional connections for the theta frequency band. The topology of the most representative functional connections among all patients with major depression indicated that the right anterior and left posterior brain parts may discriminate depressive patients from healthy controls.
Conclusions	The obtained data support our hypothesis that there is an increase in brain functional connectivity in major depression. This finding was interpreted within the semantic framework, where different specialization of left (monosemantic context) and right (polysemantic context) hemispheres is functionally insufficient in patients with depression.

Relationships reported by Fingelkurts, 2007

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	Theta wave (theta)	neurobiological system		Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior functional connections for the theta frequency band.	Positive
MDD	syndrome	Alpha wave (alpha)	neurobiological system		Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior, posterior, and left hemisphere functional connections for the alpha frequency band	Positive
Functional connectivity (short-range anterior functional connections)	brain morphology and function	Theta wave (theta)	neurobiological system		Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior functional connections for the theta frequency band	Positive
Functional connectivity (short-range posterior functional connections)	brain morphology and function	Alpha wave (alpha frequency band)	neurobiological system		These were short-range posterior functional connections for the alpha frequency band	Positive
Functional connectivity (short-range anterior functional connections)	brain morphology and function	Alpha wave (alpha frequency band)	neurobiological system		Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior functional connections for the alpha frequency band	Positive
Functional connectivity (short-range left hemisphere functional connections)	brain morphology and function	Alpha wave (alpha)	neurobiological system		Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range left hemisphere functional connections for the alpha frequency band	Positive
MDD	syndrome	Functional connectivity (short cortex functional connections)	brain morphology and function		In depressive patients the number and strength of short cortex functional connections were significantly larger for the left than for the right hemisphere	Positive
MDD	syndrome	Functional connectivity (long functional connections)	brain morphology and function		In depressive patients the number and strength of long functional connections were significantly larger for the right than for the left hemisphere.	Positive