| Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, United States. Electronic address: joseph.sakai@ucdenver.edu. |
| Division of Substance Dependence, Department of Psychiatry, University of Colorado School of Medicine, Denver, CO, USA. joseph.sakai@uchsc.ed |
| Division of Substance Dependence, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA. joseph.sakai@ucdenver.edu |
| Drs. Hartman, Gelhorn, Crowley, Sakai, and Hopfer are with the School of Medicine at the University of Colorado Health Sciences Center; Drs. Stallings, Young, Rhee, Corley, and Hewitt are with the Institute for Behavioral Genetics at the University of Colorado. |