Table 4.

Association between internet addiction and genetic polymorphisms in serotonin-transporter, dopamine active transporter 1, dopamine D4 receptor, and monoamine oxidase A among female youths.

Gene and genotype		Wald χ2 (df)	P value	ORa (95% CI)
5-HTTPRb
	S/S vs S/L+L/Lc	0.07 (1)	.78	0.78 (0.14-4.32)
	L/L vs S/S+S/Ld	0.1 (1)	.69	1.29 (0.35-4.68)
	S/Se	0.1 (2)	.91	N/Af
	S/L	0.1 (1)	.69	0.68 (0.10-4.52)
	L/L	0.1 (1)	.74	0.80 (0.20-3.08)
DAT1g
	10/10 vs 9/10+9/9c	1.1 (1)	.28	0.48(0.13-1.82)
	9/9 vs 9/10+10/10d	0.0 (1)	.78	0.78 (0.14-4.32)
	10/10e	1.6 (2)	.43	N/A
	9/10	0.06 (1)	.79	0.77 (0.11-5.24)
	9/9	0.4 (1)	.49	1.86 (0.31-11.18)
DRD4h
	4/4 vs non 4/4c	0.4 (1)	.48	1.55 (0.44-5.42)
MAO-Ai
	H/H vs H/L+L/Lc	0.2 (1)	.64	0.75 (0.22-2.55)
	L/L vs H/H+H/Ld	0.6 (1)	.41	0.50 (0.09-2.62)
	H/He	1.7 (2)	.42	N/A
	H/L	0.2 (1)	.65	0.66 (0.11-3.91)
	L/L	0.9 (1)	.31	2 (0.51-7.81)

^aOR: odds ratio.

^b5-HTTLPR: serotonin-transporter-linked polymorphic region.

^cDominant.

^dRecessive.

^eAdditive.

^f N/A: not applicable.

^gDAT1: dopamine transporter 1.

^hDRD4: dopamine D4 receptor gene.

ⁱMAO-A: monoamine oxidase A.