Ten-year follow-up after admission to methadone maintenance.

To assess the long-term effects of methadone maintenance, we compared the 10-year outcomes of 95 chronic opioid users who spent at least one cumulative year on methadone with those of 77 chronic opioid users who spent less than one cumulative year on methadone. All subjects were men and 90% were Mexican-American. The two groups were similar on 12 of 15 background variables. During the 10-year period, the methadone group had a cumulative mean of 54 months on methadone, while the comparison group had a cumulative mean of only 2 months on methadone. On social performance, as measured by months employed and months institutionalized, the methadone group did significantly better than did the comparison group. On months of voluntary abstinence, however, the comparison group did significantly better than did the methadone group. The mean of the comparison group, 36 months, was three times greater than that, 12 months, of the methadone group. At the end of the 10-year period, 26% of the comparison group but only 7% of the methadone group had been in continuous voluntary abstinence for 3 years or longer. Methadone maintenance for 1 year or longer was inversely related to abstinence during and at the end of the 10 years. This finding seems consistent with the hypothesis that methadone maintenance for 1 year or longer impedes eventual recovery from opioid dependence. For many patients, however, the benefits of prolonged maintenance could outweigh the possible cost of diminished likelihood of eventual recovery.