The available experimental studies did not demonstrate the effectiveness of AA or other 12-step approaches in reducing alcohol use and achieving abstinence compared with other treatments, but there were some limitations with these studies. Furthermore, many different interventions were often compared in the same study and too many hypotheses were tested at the same time to identify factors which determine treatment success.
Psychostimulants did not improve cocaine use, had an unclear beneficial effect over sustained cocaine abstinence and were not associated with higher retention in treatment. Psychostimulants did not increase risk of serious adverse events. It was found that psychostimulants could be efficacious for some groups of patients, such as methadone maintained dual heroin-cocaine addicts. Therefore, psychostimulants, though have not proved yet their efficacy for cocaine dependence, deserve further investigation.