[1] Univ Iowa, Coll Med, Dept Psychiat, Iowa City, IA 52242 USA
[2] Univ Iowa, Coll Publ Hlth, Dept Biostat, Iowa City, IA USA
[3] Univ No Iowa, Ctr Social & Behav Res, Cedar Falls, IA 50614 USA
[4] Univ Iowa, Iowa Consortium Substance Abuse Res & Evaluat, Iowa City, IA USA
[5] Univ No Iowa, Dept Sociol Anthropol & Criminol, Cedar Falls, IA 50614 USA