[1] Childrens Hosp, Ctr Adolescent Substance Abuse Res, Boston, MA 02115 USA
[2] Harvard Univ, Sch Med, Dept Pediat, Cambridge, MA 02138 USA
[3] Tufts New England Med Ctr Floating Hosp Children, Dept Pediat, Boston, MA USA
[4] Cambridge Hlth Alliance, Cambridge, MA USA
[5] Milton Family Pract, Milton, VT USA
[6] Univ Vermont, Coll Med, Dept Family Med, Burlington, VT 05405 USA
[7] Fallon Clin Inc, Dept Pediat, Worcester, MA USA