Neuropsychological functioning in methadone maintenance patients versus abstinent heroin abusers.

Several studies have reported on neuropsychological status as an important contributing variable in drug abuse rehabilitation outcomes. However, few studies have dealt with cognitive impairment in methadone maintenance patients (MMP), despite the fact that methadone is the most frequently used opioid substitution treatment in European countries. The objective of the present study is to contrast the neuropsychological performance of MMP with that of abstinent heroin abusers (AHA).