Changes in the amplitude of low-frequency fluctuations in specific frequency bands in major depressive disorder after electroconvulsive therapy

Table 1 Demographic data of the major depressive disorder patients and healthy controls

Characteristic	MDDs (n = 22)		HCs (n = 15)	P value
Sex (male/female)	8/14		5/10
Age (mean ± SD)	34.4 ± 10.1		36.1 ± 9.4	0.4951
Education years (mean ± SD)	11.61 ± 3.28		14.93 ± 3.64	0.0911
HAMD	Pre-ECT	30.59 ± 4.35	2.18 ± 1.32	< 0.0012
	Post-ECT	8.76 ± 5.58

¹Mann-whitney U nonparametric tests (criteria alpha = 0.05).

²Paired t tests between pre- and post-electroconvulsive therapy major depressive disorder patients. MDDs: Major depressive disorder patients; HCs: Healthy controls; HAMD: Hamilton Rating Scale for Depressive; ECT: Electroconvulsive therapy.

Table 2 Differences in amplitude of low-frequency fluctuations (0.01-0.08 Hz) between groups before and after electroconvulsive therapy

Brain region	Side	BA	MNI coordinates			Voxels	t values
			x	y	z
Before ECT < after ECT
Middle frontal gyrus	R	10, 11	30	54	3	262	3.5547
Posterior cingulate	R and L	29, 30	-3	-45	9	92	4.0993
Supramarginal gyrus	R	7, 39, 40	51	-48	30	187	3.7424
Superior frontal gyrus	L	9, 10	-12	63	24	96	3.4006
Angular gyrus	L	39, 40	-42	-72	42	193	4.0957
Before ECT > after ECT
Superior temporal gyrus	R	13, 22, 47	54	-3	0	114	-3.1055

MNI: Montreal Neurological Institute; ECT: Electroconvulsive therapy.

Table 3 Brain regions showing significant differences in amplitude of low-frequency fluctuations at slow-5 (0.01-0.027 Hz) between groups before and after electroconvulsive therapy

Brain region	Side	BA	MNI coordinates			Voxels	t values
			x	y	z
Before ECT < after ECT
Limbic lobe	R	36	33	-21	-30	105	3.0807
Cerebellum posterior lobe	R and L	18	-12	-82	-27	116	3.4515
Frontal_Mid_Orb_R	R	11	45	48	-15	187	3.7424
Frontal lobe	R	22	48	18	36	147	3.3909
Frontal lobe	R and L	6, 8, 9, 10	-6	48	54	233	4.2748
Before ECT > after ECT
Sublobar	L	22	-42	3	3	111	-4.015
Angular gyrus	R	13	39	12	-3	124	-3.1741
Frontal lobe	R	24	12	-36	48	228	-3.7067

MNI: Montreal Neurological Institute; ECT: Electroconvulsive therapy.

Table 4 Brain regions showing significant differences in amplitude of low-frequency fluctuations at slow-4 (0.027-0.08 Hz) between groups before and after electroconvulsive therapy

Brain region	Side	BA	MNI coordinates			Voxels	t values
			x	y	z
Before ECT < after ECT
Frontal lobe, superior frontal gyrus	R and L	9, 10, 11, 47	51	45	-15	243	3.3179
Parietal lobe, inferior parietal lobule	R	39, 40	57	-60	21	131	2.8756
Parietal lobe, angular gyrus	L	39, 40, 19, 7	-45	-63	36	256	4.1322
Parietal lobe	R	7	15	-69	63	129	3.9572

MNI: Montreal Neurological Institute; ECT: Electroconvulsive therapy.