Data were derived from 897 participants (513 women, mean age 19.62±1.24) who had successfully completed the ongoing Duke Neurogenetics Study (DNS) as of as of December 31, 2013. The DNS assesses a range of behavioral and biological traits among young adult, university students. The study was approved by the Duke University School of Medicine Institutional Review Board. All participants provided informed consent in accord with Duke University guidelines, and were in good general health. All participants were free of the following exclusionary criteria: (1) medical diagnoses of cancer, stroke, diabetes requiring insulin treatment, chronic kidney or liver disease, or lifetime history of psychotic symptoms; (2) use of psychotropic, glucocorticoid, or hypolipidemic medication; and (3) conditions affecting cerebral blood flow and metabolism (e.g., hypertension).
Our analyses focused on a subset of 759 participants (426 women, mean age 19.65±1.24) with BOLD fMRI data surviving a stringent multi-level quality control procedure (Supplementary Table 1). Of these 759 participants, 127 (55 women; mean age 19.79±1.21) met criteria for at least one current Axis I or select Axis II (borderline or antisocial personality disorder) diagnosis according to DSM-IV. The majority of these individuals (n=86; 35 women, mean age 19.94±1.15) were diagnosed with AUD (Supplementary Table 2). Since our study focuses on inter-individual variability in problem drinking, we did not exclude individuals with categorical disorders from analyses. Furthermore, we used presence of a current alcohol-related disorder (alcohol abuse or dependence) as a dependent variable in a subset of analyses. Notably, participants were required to pass a breathalyzer test before scanning to ensure they were not acutely intoxicated at the time of data collection. In addition, participants were asked to refrain from using any psychoactive substances while participating in the study and notified that they would be subject to a random drug screen on the day of their scan. Immediately preceding neuroimaging data collection, every 10th male participant was asked to provide a urine sample, which was tested on a QuickScreen Pro Drug Screening test (Phamatech Inc, San Diego, CA) for the presence of amphetamine, methamphetamine, opiates, cocaine and tetrahydrocannabinol (THC). Due to the pharmacokinetics of THC,33 (link) the presence of the chemical in urine was not deemed exclusionary unless the participant was acutely intoxicated. No participant was excluded for acute THC intoxication or tested positive for any other substance.