Association Between EEG Power During Sleep and Attention Levels in Patients with Major Depressive Disorder

Figures & data

Table 1 Demographic, Clinical and Sleep Characteristics

	Controls (n = 47)	Patients with MDD (n = 47)	P
Age (years)	26.55 ± 4.61	27.26 ± 5.79	0.466
Gender, (Female, %)	34 (72.3)	34 (72.3)	>0.999
BMI (kg/m^2)	21.25 ± 3.16	20.57 ± 3.50	0.181
Overweight (BMI≥24kg/m^2) (n, %)	7 (14.9)	6 (12.8)	0.765
Education levels			0.035
Junior school or below (n, %)	1 (2.1)	8 (17.0)
Senior school or above (n, %)	46 (97.9)	39 (83.0)
PSQI scores	4.81 ± 2.16	12.98 ± 3.90	<0.001
BDI scores	5.62 ± 7.24	26.94 ± 9.95	<0.001
BAI scores	5.28 ± 5.56	24.74 ± 15.25	<0.001
ESS scores	6.32 ± 3.74	6.62 ± 6.25	0.422
Sleep onset latency (minutes)	12.98 ± 10.37	24.26 ± 38.94	0.533
Total sleep time (minutes)	435.38 ± 36.43	375.09 ± 94.17	<0.001
Sleep efficiency (%)	90.68 ± 5.30	77.02 ± 18.97	<0.001
NREM sleep stage 1 (%)	9.36 ± 4.10	10.84 ± 7.70	0.901
NREM sleep stage 2 (%)	47.59 ± 6.32	48.49 ± 10.80	0.625
NREM sleep stage 3 (%)	22.68 ± 6.23	22.52 ± 10.06	0.926
REM sleep (%)	20.33 ± 4.06	18.15 ± 6.90	0.065
REM sleep latency (minutes)	108.71 ± 40.30	148.86 ± 101.08	0.309
Wake time after sleep onset (minutes)	31.12 ± 21.01	87.77 ± 77.50	<0.001
AHI (events/hour)	1.20 ± 1.11	1.74 ± 1.52	0.148

Notes: Data are presented as mean ± standard deviation for continuous variables, and sample size (percentage) for categorical variables. P-values are given for the comparison of the characteristic between patients with MDD and controls. P-values ≤ 0.05 are indicated in bold.

Abbreviations: AHI, apnea hypopnea index; BAI, Beck Anxiety Inventory; BDI, Beck Depression Inventory; BMI, body mass index; ESS, Epworth Sleepiness Scale; MDD, major depressive disorder; NREM, non-rapid eye movement; PSQI, Pittsburgh Sleep Quality Index; REM, rapid eye movement.

Table 2 EEG Power of Controls and Patients with MDD

EEG Power	Controls (n = 47)	Patients with MDD (n = 47)	P	η^2p
NREM-delta (%)	77.63 ± 0.64	78.04 ± 0.64	0.653	0.002
NREM-theta (%)	11.06 ± 0.29	10.06 ± 0.29	0.018	0.061
NREM-alpha (%)	4.58 ± 0.23	4.47 ± 0.23	0.746	0.001
NREM-sigma (%)	4.78 ± 0.31	5.14 ± 0.31	0.411	0.008
NREM-beta (%)	1.90 ± 0.12	2.22 ± 0.12	0.050	0.042
NREM-gamma (%)	0.05 ± 0.01	0.06 ± 0.01	0.095	0.031
REM-delta (%)	64.73 ± 0.87	67.70 ± 0.87	0.018	0.060
REM-theta (%)	17.97 ± 0.43	16.02 ± 0.43	0.002	0.103
REM-alpha (%)	7.30 ± 0.32	6.43 ± 0.32	0.061	0.039
REM-sigma (%)	3.89 ± 0.16	3.63 ± 0.16	0.263	0.014
REM-beta (%)	5.96 ± 0.44	6.05 ± 0.44	0.883	<0.001
REM-gamma (%)	0.17 ± 0.01	0.18 ± 0.01	0.728	0.001

Notes: Data are presented as mean ± SEM. P-values and η²_p were derived from the ANCOVA analysis, and the model was adjusted for age and gender. P-values ≤ 0.05 are indicated in bold.

Abbreviations: ANCOVA, Analysis of covariance; EEG, electroencephalogram; MDD, major depressive disorder; NREM, non-rapid eye movement; REM, rapid eye movement; SEM, standard error of the mean.

Table 3 Attention Levels of Controls and Patients with MDD

	Controls (n = 47)	Patients with MDD (n = 47)	P	η^2p
Accuracy (%)	97.41 ± 1.02	93.95 ± 1.02	0.021	0.059
Mean RT (ms)	569.18 ± 15.56	646.79 ± 15.56	<0.001	0.120
Alerting (ms)	52.04 ± 4.15	39.46 ± 4.15	0.038	0.048
Orienting (ms)	56.45 ± 4.02	47.20 ± 4.02	0.113	0.028
Executive control (ms)	87.33 ± 7.16	108.01 ± 7.16	0.048	0.044

Notes: Data are presented as mean ± SEM. P-values and η²_p were derived from the ANCOVA analysis, and the model was adjusted for age, gender, body mass index and education levels. P-values ≤ 0.05 are indicated in bold.

Abbreviations: ANCOVA, Analysis of covariance; ANT, Attention Network Test; MDD, major depressive disorder, RT, reaction time; SEM, standard error of the mean.

Table 4 Association Between EEG Power and ANT Index in Patients with MDD and Control Subjects

	Accuracy (%)			Mean RT (ms)			Alerting (ms)			Executive Control (ms)
	B	β	P	B	β	P	B	β	P	B	β	P
Patients with MDD (n = 47)
NREM-theta (%)	1.767	0.329	0.040	−7.004	−0.090	0.583	−1.057	−0.065	0.710	−4.315	−0.136	0.465
NREM-beta (%)	0.548	0.051	0.727	−38.386	−0.247	0.087	−5.432	−0.167	0.281	−3.552	−0.056	0.737
REM-delta (%)	−0.228	−0.140	0.335	7.642	0.325	0.022	−0.697	−0.142	0.362	1.605	0.167	0.313
REM-theta (%)	0.005	0.001	0.993	−7.802	−0.136	0.358	4.254	0.355	0.020	−2.180	−0.093	0.580
Control subjects (n = 47)
NREM-theta (%)	0.050	0.068	0.694	4.500	0.174	0.274	0.612	0.059	0.726	0.166	0.014	0.933
NREM-beta (%)	0.230	0.075	0.621	−20.580	−0.195	0.166	−3.742	−0.087	0.554	−15.455	−0.316	0.026
REM-delta (%)	−0.024	−0.077	0.645	1.649	0.154	0.321	0.296	0.068	0.674	0.975	0.196	0.217
REM-theta (%)	−0.018	−0.031	0.838	0.908	0.046	0.747	0.200	0.025	0.867	0.433	0.047	0.748

Notes: The linear models adjusted for age, gender, body mass index, and education levels. P-values ≤ 0.05 are indicated in bold.

Abbreviations: ANT, Attention Network Test; B, unstandardized coefficients; β, standardized coefficient; EEG, electroencephalogram; MDD, major depressive disorder; NREM, non-rapid eye movement; REM, rapid eye movement; RT, reaction time.

Data Sharing Statement

Data and protocols are available upon reasonable request. Data and protocols are available on request from the corresponding author.