. Author manuscript; available in PMC: 2017 Feb 28.

Published in final edited form as: Dev Psychopathol. 2015 Dec 9;28(4 Pt 2):1441–1456. doi: 10.1017/S0954579415001182

Table 3.

Do Adolescents with versus without the DRD4-7R allele witness substance use (SU) more often?

	DRD4-7R+ (n=50)	DRD4-7R- (n=91)	Genotype Differences

	M (SD)	M (SD)	t(df=139)	p
Witnessed SU Home or Outside Home	0.094 (0.131)	0.092 (0.157)	0.07	0.94
Witnessed SU at Home	0.032 (0.080)	0.026 (0.083)	−0.38	0.70
Witnessed SU Outside Home	0.076 (0.109)	0.077 (0.128)	0.05	0.96

Note. M=sample mean of adolescent-specific proportions for witnessing substance use across days, SD=standard deviation in these proportions.

DRD4-7R+: 7R present; DRD4-7R-: 7R absent.