[1] Univ Minnesota, Dept Behav Sci, Sch Med, Duluth, MN 55812 USA
[2] Univ Minnesota, Duluth Med Res Inst, Sch Med, Duluth, MN 55812 USA
[3] Univ Minnesota, Dept Physiol & Pharmacol, Sch Med, Duluth, MN 55812 USA
[4] Univ Minnesota, Dept Family Med, Sch Med, Duluth, MN 55812 USA
[5] Heidelberg Univ, Dept Addict Behav & Addict Med, Cent Inst Mental Hlth, D-68159 Mannheim, Germany