Sleep disturbances and psychomotor retardation in the prediction of cognitive impairments in patients with major depressive disorder

Table 5 Simple mediation analysis for the relationship between psychic anxiety symptoms and cognitive performance

Mediating variable (M)	Independent variable (X)	Dependent variable (Y)	X→M	M→Y	Indirect effect1	Direct effect1
Sleep disturbances	HAMA-psychic symptoms	Executive function	0.285c	-0.048	-0.013 [-0.027, -0.001]1	-0.027 [-0.054, 0.001]
Sleep disturbances	HAMA-psychic symptoms	Processing speed	0.285c	-0.063	-0.018 [-0.042, 0.007]	-0.037 [-0.086, 0.012]
Sleep disturbances	HAMA-psychic symptoms	Memory	0.285c	-0.522c	-0.149 [-0.237, -0.063]1	-0.075 [-0.232, 0.081]
Retardation	HAMA-psychic symptoms	Processing speed	0.241c	-0.097a	-0.023 [-0.045, -0.004]1	-0.031 [-0.077, 0.014]

^aP < 0.05.

^cP < 0.001.

¹Significant point estimates (P < 0.05) as determined by the exclusion of zero from the confidence interval.