[1] Univ N Carolina, Sch Med, Dept Social Med, Chapel Hill, NC 27599 USA
[2] Univ N Carolina, Dept Family Med, Chapel Hill, NC 27599 USA
[3] Boston Univ, Dept Psychiat, Boston, MA 02215 USA
[4] Boston Univ, Dept Psychol, Boston, MA 02215 USA
[5] VA Boston Healthcare Syst, Boston, MA USA