1 Department of Psychology, Columbia University, New York, NY 10027; Division on Substance Abuse, Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 1051 Riverside Dr., Unit 120, New York, NY 10032.
2 Department of Psychology, Columbia University, New York, NY 10027; Division on Substance Abuse, Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 1051 Riverside Dr., Unit 120, New York, NY 10032. Electronic address: clh42@columbia.edu.