[1] Duke Univ, Dept Psychol & Neurosci, Durham, NC 27705 USA
[2] Duke Univ, Dept Psychiat & Behav Sci, Durham, NC 27705 USA
[3] Duke Univ, Inst Genome Sci & Policy, Durham, NC 27705 USA
[4] Kings Coll London, Inst Psychiat, Social Genet & Dev Psychiat Res Ctr, London SE5 8AF, England
[5] Univ Otago, Dept Prevent & Social Med, Sch Med, Dunedin Multidisciplinary Hlth & Dev Res Unit, Dunedin, New Zealand
[6] Univ Otago, Sch Dent, Dept Oral Sci & Orthodont, Dunedin, New Zealand
[7] Univ Illinois, Dept Psychol, Champaign, IL 61820 USA
[8] McMaster Univ, Dept Med, Hamilton, ON L8S 4L8, Canada
[9] Firestone Inst Resp Hlth, Hamilton, ON L8N 4A6, Canada