RT Journal
A1 Silverman K, Higgins ST, Brooner RK, et al
T1 SUstained cocaine abstinence in methadone maintenance patients through voucher-based reinforcement therapy
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 1996
FD May 1
VO 53
IS 5
SP 409
OP 415
DO 10.1001/archpsyc.1996.01830050045007
UL http://dx.doi.org/10.1001/archpsyc.1996.01830050045007
AB Background: 
    Chronic cocaine abuse remains a serious and costly public health problem. This study assessed the effectiveness of a voucher-based reinforcement contingency in producing sustained cocaine abstinence.Methods: 
    A randomized controlled trial compared voucherbased reinforcement of cocaine abstinence to noncontingent voucher presentation. Patients were selected from 52 consecutively admitted injecting heroin abusers in a methadone maintenance treatment program. Patients with heavy cocaine use during baseline period (N=37) participated. Except where otherwise indicated, the term cocaine abuse is used in this article in a generic sense and not according to the DSM-III-R definition. Patients exposed to abstinence reinforcement received a voucher for each cocaine-free urine sample (ie, negative for benzoylecgonine) provided three times per week throughout a 12-week period; the vouchers had monetary values that increased as the number of consecutive cocaine-free urine samples increased. Control patients received noncontingent vouchers that were matched in pattern and amount to the vouchers received by patients in the abstinence reinforcement group.Results: 
    Patients receiving vouchers for cocaine-free urine samples achieved significantly more weeks of cocaine abstinence (P=.007) and significantly longer durations of sustained cocaine abstinence (P=.001) than controls. Nine patients (47%) receiving vouchers for cocaine-free urine samples achieved between 7 and 12 weeks of sustained cocaine abstinence; only one control patient (6%) achieved more than 2 weeks of sustained abstinence. Among patients receiving vouchers for cocaine-free urine samples, those who achieved sustained abstinence (≥5 weeks) had significantly lower concentrations of benzoylecgonine in baseline urine samples than those who did not achieve sustained abstinence (P≤.01). Patients receiving voucher reinforcement rated the overall treatment quality significantly higher than controls (P=.002).Conclusion: 
    Voucher-based reinforcement contingencies can produce sustained cocaine abstinence in injecting polydrug abusers.