edition of the Diagnostic and Statistical Manual of Mental Disorders [DSM–IV]; American Psychiatric Association, 1994), or any current or past medical condition considered to be a contraindication for d-amphetamine (e.g., abnormal EKG or hypertension). Candidates had to speak English and have at least a high school education. Their body mass index (BMI) had to be in the range between 19 and 26kg/m2. To minimize the influence of hormones, women were tested only during the follicular phase (White, Justice, & de Wit, 2002). Women who were pregnant, lactating, or planning to become pregnant during the study were excluded from participation. The study was approved by The University of Chicago Institutional Review Board.
