Abstract
Advantage was taken of a natural experiment to compare the outcome of abstinence-oriented and indefinite methadone maintenance. Subjects assigned to an abstinence-oriented program were significantly more likely than those assigned to indefinite maintenance to use heroin (OR 1.3) and amphetamines (OR 2.8) during the first 2 years of methadone treatment but less likely to use benzodiazepines (OR 0.7). Subjects discharged from the abstinence-oriented program were significantly more likely to relapse and return to maintenance treatment (RR, first 6 months, 4.2). The abstinence-oriented program was also less able to attract heroin addicts into maintenance treatment.