Table 3.

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

Gene and genotype		Wald χ2 (df)	P value	ORa (95% CI)
5-HTTPRb
	S/S vs S/L+L/Lc	0.5 (1)	.47	1.57 (0.45-5.45)
	L/L vs S/S+S/Ld	0.001 (1)	.97	0.98 (0.26-3.66)
	S/Se	0.5 (2)	.75	N/Af
	S/L	0.05 (1)	.67	1.4 (0.29-6.62)
	L/L	0.3 (1)	.80	0.84 (0.20-3.45)
DAT1g
	10/10 vs 9/10+9/9c	0.1 (1)	.73	0.81 (0.25-2.65)
	9/9 vs 9/10+10/10d	0.7 (1)	.39	2.25 (0.34-14.83)
	10/10e	0.7 (2)	.69	N/A
	9/10	0.6 (1)	.40	0.42 (0.05-3.21)
	9/9	0.6 (1)	.43	0.45 (0.06-3.21)
DRD4h
	4/4 vs non 4/4c	0.5 (1)	.47	0.65 (0.21-2.06)
MAO-Ai
	H vs Lj	0.007 (1)	.93	0.95 (0.29-3.11)
	L vs H	0.007(1)	.93	1.05 (0.32-3.45)

^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.

^jAllelic.