Abstract
The authors have previously shown an effect of dopamine transporter genotype on acute subjective responses to d-amphetamine, which may affect risk of addiction. They now report the results of an evaluation of the role of the serotonin transporter gene (HTT) using a double-blind, placebo-controlled, crossover design in which subjects (N = 101) completed self-report measures of subjective effect. The separate and combined analyses of the gene-linked polymorphic region (5-HTTLPR) and the Intron 2 VNTR suggest that these two HTT polymorphisms may contribute to acute subjective responses to d-amphetamine with a small effect.