Effect of insomnia on anxiety and depression: Mediation of cognitive failures and moderated mediation of neuroticism

Table 1 Mental health status of participants (n = 1011), n (%)

Degree	Anxiety	Depression	Insomnia
No	593 (58.7)	560 (55.4)	644 (63.7)
Mild	265 (26.2)	273 (27.0)	282 (27.9)
Moderate	105 (10.4)	100 (9.9)	73 (7.2)
Severe	48 (4.7)	78 (7.7)	12 (1.2)

Table 2 Comparison of mental health among participants with different demographic characteristics, n (%)

Variable	Category		Generalized anxiety disorder-7	Patient health questionaire-9	Insomnia severity index
Sex	Male	343 (33.9)	4.59 ± 4.80	5.14 ± 5.15	6.14 ± 5.41
	Female	668 (66.1)	4.43 ± 4.93	5.33 ± 5.60	6.24 ± 5.41
	t value		0.491	-0.507	-0.273
Ethnicity	Han	996 (98.5)	4.48 ± 4.89	5.25 ± 5.44	6.20 ± 5.42
	Other	15 (1.5)	5.00 ± 4.28	6.40 ± 6.14	6.33 ± 5.19
	t value		0.680	0.146	0.926
Age (years)	18-25	354 (35.0)	4.32 ± 4.72	5.22 ± 5.45	6.28 ± 5.46
	26-50	563 (55.7)	4.79 ± 5.01	5.56 ± 5.49	6.17 ± 5.32
	> 50	94 (9.3)	3.28 ± 4.47	3.65 ± 5.00	6.12 ± 5.78
	F value		4.162a	5.005b	0.053
Education	High school or below	77 (7.6)	5.79 ± 5.33	6.70 ± 6.60	7.40 ± 6.35
	College degree	164 (16.2)	4.41 ± 4.82	5.45 ± 5.56	6.55 ± 5.92
	Bachelor degree	440 (43.5)	4.41 ± 4.85	5.15 ± 5.25	5.93 ± 5.17
	Master degree or above	330 (32.6)	4.31 ± 4.82	4.99 ± 5.33	6.11 ± 5.20
	F value		2.033	2.194	1.892
Only child	Yes	281 (27.8)	5.17 ± 4.98	5.85 ± 5.45	6.83 ± 5.47
	No	730 (72.2)	4.22 ± 4.82	5.04 ± 5.44	5.96 ± 5.37
	t value		2.772b	2.139a	2.295a

^aP < 0.05.

^bP < 0.01.

Table 3 Correlation between neuroticism, cognitive failures, and mental health

	Neuroticism	CFQ	GAD-7	PHQ-9	ISI
Neuroticism	1.000
CFQ	0.454b	1.000
GAD-7	0.608b	0.430b	1.000
PHQ-9	0.579b	0.504b	0.786b	1.000
ISI	0.410b	0.454b	0.518b	0.611b	1.000

^bP < 0.01.

CFQ: Cognitive failures questionnaire; GAD-7: Generalized anxiety disorder-7; PHQ-9: Patient health questionaire-9; ISI: Insomnia severity index.

Table 4 The total effect, indirect effect, and direct effect between insomnia severity index and generalized anxiety disorder-7

	Effect	Boot SE	Bootstrapped 95%CI		Relative effects
			Lower limit	Upper limit
Total effect	0.462	0.024	0.414	0.510
Mediation effect of cognitive failures questionnaire	0.104	0.015	0.076	0.133	22.51%
Direct effect	0.358	0.026	0.306	0.410	77.49%

The Boot SE and Bootstrapped 95%CI respectively refer to the standard error and the 95%CI of the indirect effects estimated by the percentile Bootstrap method of deviation correction. All values are rounded to the nearest three decimal places.

Table 5 The total effect, indirect effect, and direct effect between insomnia severity index and patient health questionaire-9

	Effect	Boot SE	Bootstrapped 95%CI		Relative effects
			Lower limit	Upper limit
Total effect	0.610	0.025	0.561	0.660
Mediation effect of cognitive failures questionnaire	0.132	0.015	0.104	0.163	21.64%
Direct effect	0.478	0.027	0.426	0.531	78.36%

The Boot SE and Bootstrapped 95%CI respectively refer to the standard error and the 95%CI of the indirect effects estimated by the percentile Bootstrap method of deviation correction. All values are rounded to the nearest three decimal places.

Table 6 Bootstrap confidence intervals for the moderated mediation effects with dependent variable of anxiety

Predictors	Cognitive failures (M)				Anxiety (dependent variable)
	Coeff	SE	t value	95%CI	Coeff	SE	t value	95%CI
Insomnia (X)	0.849c	0.072	11.742	0.707-0.991	0.358c	0.026	13.574	0.307-0.410
Cognitive failures (M)					0.096c	0.011	8.614	0.074-0.118
Neuroticism (W)	0.605c	0.055	11.094	0.498-0.712
X × W	-0.025b	0.008	-3.309	-0.040 to 0.010
Constant	21.748c	2.659	8.178	16.529-26.966	4.506c	1.025	4.398	2.495-6.517
		R2 = 0.311				R2 = 0.325
		F = 56.525, P < 0.001				F = 69.098, P < 0.001

^bP < 0.001.

^cP < 0.001.

Coeff: Coefficient; M: Mediator; W: Moderator; X: Independent variable.

Table 7 Bootstrap confidence intervals for the moderated mediation effects with dependent variable of depression

Predictors	Cognitive failures (M)				Depression (dependent variable)
	Coeff	SE	t value	95%CI	Coeff	SE	t value	95%CI
Insomnia (X)	0.849c	0.072	11.742	0.707-0.991	0.479c	0.027	17.814	0.427-0.532
Cognitive failures (M)					0.122c	0.011	10.783	0.099-0.144
Neuroticism (W)	0.605c	0.055	11.094	0.498-0.712
X × W	-0.025b	0.008	-3.309	-0.040 to -0.010
Constant	21.748c	2.659	8.178	16.529-26.966	4.117c	1.038	3.965	2.079-6.155
		R2 = 0.311				R2 = 0.444
		F = 56.525, P < 0.001				F = 114.639, P < 0.001

^bP < 0.001.

^cP < 0.001.

Coeff: Coefficient; M: Mediator; W: Moderator; X: Independent variable.

Table 8 The mediating effect of cognitive failures on insomnia and anxiety at different neurotic levels

Neuroticism	Effect	Boot SE	Bootstrapped 95%CI
			Lower limit	Upper limit
-6.941 (M-1SD)	0.098	0.013	0.072	0.126
0 (M)	0.081	0.011	0.06	0.103
6.941 (M+1SD)	0.064	0.011	0.043	0.088

The Boot SE and Bootstrapped 95%CI respectively refer to the standard error and the 95%CI of the indirect effects estimated by the percentile Bootstrap method of deviation correction. All values are rounded to the nearest three decimal places. M: Mediator.

Table 9 The mediating effect of cognitive failures on insomnia and depression at different neurotic levels

Neuroticism	Effect	Boot SE	Bootstrapped 95%CI
			Lower limit	Upper limit
-6.941 (M-1SD)	0.125	0.016	0.096	0.158
0 (M)	0.103	0.013	0.080	0.130
6.941 (M+1SD)	0.082	0.013	0.057	0.110

The Boot SE and Bootstrapped 95%CI respectively refer to the standard error and the 95%CI of the indirect effects estimated by the percentile Bootstrap method of deviation correction. All values are rounded to the nearest three decimal places. M: Mediator.