Table 1.
MEG resting-state connectivity studies in major depressive disorder.
| Reference | Frequency range | Methods | Patients | Controls | Main findings |
|---|---|---|---|---|---|
| (129) | Delta: 2–4 Hz Theta: 4–8 Hz Alpha 8–13 Hz Beta: 13–30 Hz Gamma: 30–50 Hz |
Frontal alpha asymmetry and voxel-based partial correlation to examine connectivity in prefrontal-thalamic circuit (based on PET) Sensor-space analysis 3 min eyes open |
30 MDD received rTMS, 6 males 17 responders: mean age: 51.9 ± 10.5 13 non-responders: mean age: 50.1 ± 6.2 |
50 controls 14 males mean age: 49.1 ± 7.0 |
MDD appeared to have impaired prefronto-thalamic functional connections compared to controls. rTMS resolved this pattern in those who responded to treatment after 2 weeks of treatment at 10 Hz in their dorsolateral PFC |
| (132) | 14–30 Hz | Correlation Source-space analysis 4.17 min eyes closed |
33 MDD 22 males Mean age: 42.8 ± 9.9 |
19 controls 11 males Mean age: 39.3 ± 6.5 |
Patients had reduced correlations between the subgenual ACC and hippocampus in a network with primary nodes in the precentral and middle frontal gyri. Patients showed increased correlations between insulotemporal nodes and amygdala compared to controls |
| (133) | 14–30 Hz | Correlation Source space 4.17 min eyes closed |
13 MDD 11 males Mean age: 45.0 ± 13.2 |
18 controls 12 males Mean age: 39.0 ± 7.3 |
Patients displayed enhanced connectivity between insulotemporal areas and amygdala that were reduced to normal levels after ketamine treatment |
| (134) | Delta: 2–4 Hz Theta: 5–7 Hz Alpha: 8–12 Hz Beta: 15–29 Hz Gamma: 30–59 Hz |
Magnitude-squared coherence. Seed: dorsolateral PFC Source space 6 min eyes closed |
5 MDD received TMS, 1 non-responder | n/a | Symptom improvement by 10 Hz rTMS increased connectivity between dorsolateral PFC and amygdala, and dorsolateral PFC and pregenual ACC in delta band. rTMS decreased connectivity between dorsolateral PFC and subgenual ACC |
Overview of MEG resting-state studies examining changes in long-range connectivity patterns in subjects with MDD.
MDD, major depressive disorder; rTMS, repetitive transcranial magnetic stimulation; PFC, prefrontal cortex; ACC, anterior cingulate cortex; MEG, magnetoencephalography.