Written assent was obtained from the participants and written informed consent was obtained from the parents before commencing the research protocols. Beginning at age 18, the participants provided informed consent. Privacy was additionally protected by a certificate of confidentiality issued to the Center for Education and Drug Abuse Research by the National Institute on Drug Abuse. Once the youngster was deemed qualified to participate, an alcohol Breathalyzer test and urine screen were performed to ensure that the results were not confounded or biased by a substance-induced physiological state. A positive finding required rescheduling the participant. The measures were individually administered in sound-attenuating rooms in fixed order by experienced research associates. Following completion of each evaluation session, the participant was debriefed and compensated at the rate of approximately $10/hr.
