[1] Natl Inst Drug Abuse, NIH, Intramural Res Program, Translat Addict Med Branch, Baltimore, MD USA
[2] Johns Hopkins Univ, Dept Mental Hlth, Baltimore, MD USA
[3] Natl Human Genome Res Inst, NIH, Social & Behav Res Branch, Div Intramural Res, Bethesda, MD USA
[4] Johns Hopkins Univ, Sch Med, Dept Med, Div Addict Med, Baltimore, MD USA
[5] Brown Univ, Sch Publ Hlth, Dept Behav & Social Sci, Ctr Alcohol & Addict Studies, Providence, RI USA
[6] Georgetown Univ, Med Ctr, Dept Neurosci, Washington, DC USA
[7] NIH, Bethesda, MD 20892 USA