1. Department of Psychiatry and Behavioral Sciences; Baylor College of Medicine; Houston Texas
2. Department of Alcohol and Drug Dependence; Beijing Hui-Long-Guan Hospital; Peking University; Beijing China
3. National Institute on Drug Dependence; Peking University; Beijing China
4. Department of Psychiatry, Neuroscience, and Pharmacology; Baylor College of Medicine; Houston Texas
5. Michael E. DeBakey Veteran Affairs Medical Center; Houston Texas