The first 91 Caucasian participants (47 women; mean age 19.66±1.36) to complete the ongoing Duke Neurogenetics Study (DNS) were selected for inclusion in analyses involving methylation assays. The DNS assesses a range of behavioral and biological traits among young adult, student volunteers. All participants provided informed consent in accord with Duke University guidelines, and were in good general health. Two participants’ samples displayed wrong sequence patterns for our SLC6A4 promoter assays due to unknown mutations or equipment dispensation error and were thus excluded for this analysis. Nine additional participants were excluded due to task non-compliance or response box failure leaving a final sample of 80 individuals (42 women; mean age 19.74 ± 1.33).
