Tardive dyskinesia-depression association in Chinese patients with chronic schizophrenia: The mediating role of insomnia and gender differences

Table 2 Mediating effect of insomnia on the relationship between tardive dyskinesia and depression

	Effect1	Coefficient	SE	t	P value	95%CI
						LL	UL
DV: Depression; IV: Tardive dyskinesia; mediator: Insomnia	a	0.245	0.049	5.031	< 0.001	0.150	0.341
	b	0.744	0.059	12.581	< 0.001	0.628	0.860
	c	0.480	0.080	5.994	< 0.001	0.323	0.638
	c’	0.298	0.073	4.081	< 0.001	0.154	0.441
	c-c’	0.183	0.045	-	-	0.099	0.276

¹Coefficients are unstandardized regression coefficients.

a: The effect of tardive dyskinesia on insomnia; b: The effect of insomnia on depression; c: The total effect of tardive dyskinesia on depression; c’: The direct effect of tardive dyskinesia on depression after controlling for insomnia; c-c’: The indirect effect of tardive dyskinesia on depression through insomnia; SE: Standard error; CI: Confidence interval; LL: Lower limit; DV: Upper limit; IV: Independent variable; UL: Dependent variable.