My. Iguchi et al., REINFORCING OPERANTS OTHER THAN ABSTINENCE IN DRUG-ABUSE TREATMENT - AN EFFECTIVE ALTERNATIVE FOR REDUCING DRUG-USE, Journal of consulting and clinical psychology, 65(3), 1997, pp. 421-428
This study examines the effectiveness of using vouchers to reinforce e
ither the provision of urine samples testing negative for illicit drug
s (UA group) or the completion of objective, individually defined, tre
atment-plan-related tasks (TP group). A third group was assigned to th
e clinic's standard treatment (STD group). Participants were randomly
assigned to groups after a B-week baseline-stabilization period. Urine
specimens were collected thrice weekly throughout the study. In the U
A condition, participants earned $5 (U.S. dollars) in vouchers for eac
h drug-free urine submitted. In the TP condition, participants earned
up to $15 in vouchers per week for demonstrating completion of treatme
nt plan tasks assigned by their counselors. Contingencies were in effe
ct for 12 weeks, after which all participants received the clinic's st
andard treatment. Urinalysis results indicate that the TP intervention
was significantly more effective in reducing illicit drug use than ei
ther the UA or STD interventions. These effects were maintained with a
trend toward continuing improvement for the TP groups even after cont
ingencies were discontinued.