Alternative reinforcers differentially modify cocaine self-administration by humans

Six experienced cocaine smokers (two men, four women) participated in an in patient study to compare self-administration of smoked cocaine when either a $5 money or merchandise voucher was available as an alternative reinforce r, A six-trial choice procedure was used, with sessions consisting of (1) o ne sample trial, where participants received the cocaine dose and the alter native reinforcer available that day, and (2) five choice trials, where par ticipants chose between the available cocaine dose and the alternative rein forcer, There were eight sessions: in separate sessions, each dose of cocai ne (0, 12, 25, 50 mg) was paired with a money voucher and with a merchandis e voucher, The choice to self-administer cocaine significantly increased wi th escalating cocaine doses, and significantly less cocaine was self-admini stered when money vouchers were available as compared to merchandise vouche rs. These data demonstrate that money vouchers are a more effective alterna tive reinforcer than merchandise vouchers in cocaine abusers. (C) 2000 Lipp incott Williams & Wilkins.