Most empirical studies on genetic moderation of intervention effects have focused on genetic variants involved in the regulation of the dopaminergic (e.g., dopamine receptor D4 DRD4; dopamine receptor D2 DRD2; dopamine transporter gene DAT1) and serotonergic (e.g., the serotonin transporter gene linked polymorphic repeat 5-HTTLPR) neurotransmitter systems. Meta-analysis has supported their roles as susceptibility genes (van Ijzendoorn and Bakermans-Kranenburg 2015). To our knowledge, there are currently five empirical RCT studies that have examined genetic moderation of intervention effects on adolescent alcohol use, finding supportive evidence of genetic differences in intervention susceptibility among AAs (Beach et al. 2010; Brody et al. 2009b, 2013, 2014) and predominantly EAs (Cleveland et al. 2015). Most of these studies focused on DRD4 (Beach et al. 2010; Brody et al. 2013, 2014; Cleveland et al. 2015), while some also examined 5-HTTLPR (Brody et al. 2009b; Cleveland et al. 2015), and DRD2 and γ–aminobutyric acid (GABA) receptor coding genes (Brody et al. 2013).
