Table 4.

Multiple linear regression models of the associations between serum IGF-1 levels (ng/ml) and cognitive tests` performance (n = 125) ^a

Variables	Model 1		Model 2		Model 3
	β (SE)	St. β	β (SE)	St. β	β (SE)	St. β
RAVLT immediate recall	−3.55 (0.87)	− 0.35**	− 1.47 (1.10)	− 0.14	− 1.48 (1.08)	− 0.15
TMT-B	1.29 (0.34)	0.34**	0.63 (0.38)	0.17	0.52 (0.38)	0.14
DSST	−2.93 (0.71)	−0.38**	−1.77 (0.76)	− 0.23*	− 1.62 (0.75)	−0.21*

^a IGF-1 level was entered as a dependent outcome and each cognitive test score as independent variables, along with increasing confounder adjustment. β (SE) and standardized β are presented. Model 1 = adjusted for age, gender, and education, Model 2 = Model 1 + depression severity (according to MADRS), Model 3 = Model 2 + number + duration of DE; SE, standard error; *p < 0.05; **p < 0.0001