Table 2.

Statistics of three conditions for establishing a mediation model that describes how the influence of an independent variable (IV, sleep disturbance) on a dependent variable (DV, depressive symptom) is intervened by a mediating variable (MV, grey matter volume).

Condition	Regression	Effect	Brain region	t value	p value
1	DV ~ IV	IV on DV		3.3740	0.0021*
2	MV ~ IV	IV on MV	Left PostCG	−3.1399	0.0038*
			Right PostCG	−3.6766	0.0009*
			Right PCL	−2.5833	0.0149*
			Left STG	−3.1953	0.0033*
3	DV ~ IV + MV	MV on DV	Left PostCG	−2.3998	0.0230*
			Right PostCG	−0.5548	0.5833
			Right PCL	−1.6160	0.1169
			Left STG	−3.8116	0.0007*

PostCG, postcentral gyrus; PCL, paracentral lobule; STG, superior temporal gyrus; and *, statistical significance.