[1] Vet Affairs Boston Healthcare Syst, Natl Ctr Posttraumat Stress Disorder, Boston, MA USA
[2] Massachusetts Gen Hosp, Dept Med, Tobacco Res & Treatment Ctr, Boston, MA 02114 USA
[3] Univ Calif Irvine, Dept Psychol & Social Behav, Irvine, CA USA
[4] San Francisco Gen Hosp, Dept Med, Div Clin Pharmacol, San Francisco, CA 94110 USA