Changes in cocaine use after entry to methadone treatment.

A cohort sample of 93 addicts admitted to methadone maintenance in four clinics was followed-up for one year to determine change, and predictors of change, in cocaine use. Any use of cocaine in the preceding month decreased from 84% of subjects at admission to 66% at follow-up, and mean days of cocaine use per month for those still using decreased from 16 days to 9 days. Any drug injection in the preceding month decreased from 100% of subjects at admission to 39% at follow-up, among those remaining in the program. Continuance/cessation of cocaine use was not associated with program retention, but cocaine users were more likely to be administratively discharged. Reported symptoms of depression and speedballing at admission were significant predictors of continuance/cessation of cocaine use at follow-up. State-of-the-art cocaine abuse treatment, with attention to treatment of depression, would enhance the value of methadone maintenance for patients with dual heroin/cocaine addiction.