We performed a GWAS for subjective response to d-amphetamine in a small sample of healthy, non-drug abusing participants who were phenotyped using a laboratory-based, double-blind, placebo-controlled, within-subjects design, using 5.4 million genotyped or imputed SNPs. Phenotypic data were summarized using SFA, which yielded ten generally interpretable factors that represented both drug-independent and drug response phenotypes. We identified a SNP in the CDH13 gene (Figure 2) that was associated with the degree of positive response to amphetamine. We also identified a SNP in the SRD5A1 gene (Figure 3) that was potentially associated with the degree of positive affect of the participants, independent of dose.
