Laboratory data were analyzed using mixed models with the following independent variables: age, sex, race (EA or AA), FKBP5 rs3800373 (coded as minor allele carrier versus TT to increase power), ordered experimental dose (saline, 0.5 mg nicotine and 1 mg nicotine per 70 kg body weight) and the interaction of experimental dose with FKBP5 genotype (as fixed effects), and subject (as a random effect). Rs3800373 distributions are show in Table S1 and S2. Based on prior work suggesting that the DEQ items may not represent independent constructs,39 we factor analyzed the DEQ prior to conducting statistical analyses and found evidence for the following three domains: 1) “stimulatory” effects comprising “feel stimulated”, “feel effects” and “feel high”; 2) “feel good” effects comprising “like”, “feel good” and “want more”; and 3) “negative” effects comprising “feel anxious”, “feel down” and “feel bad”. Each response was rated on a visual 100 mm scale that was then converted to a rating from 1-10. Blood cortisol levels were collected at five time points described in Figure 3. Log-transformed cortisol levels were analyzed in mixed models that
