Cross-validation of a heroin addiction scale from the MMPI on an outpatient sample of heroin addicts and vocational rehabilitation clients

Many studies have attempted to discriminate addicts from non-addicts on the basis of MMPI profiles and/or auxiliary scales designed for that purpose. The present study focused on a heroin addiction (He) scale of the MMPI which successfully discriminated addicts from nonaddicts in a prison population as well as addicts from alcoholics in a psychiatric population. The majority of studies of addicts have been done in institutional settings, i.e. prisons or hospitals. The present study used an outpatient sample of heroin addicts and vocational rehabilitation clients in order to crossvalidate and extend the use of the scale. The profiles of 97 heroin addicts, 76 males and 21 females, and 70 non-drug using vocational rehabilitation clients were compared. The groups were similar with respect to age, education, and male to female ratio. Significant differences on scale elevations between the two groups were found to exist. The heroin addicts obtained substantially higher elevations than the vocational rehabilitation clients, although the pattern was similar for both groups. The He scale successfully discriminated addicts from non-addicts and in fact was the best predictor of group status, i.e. addict versus non-addict, among all the variables. It was concluded that the scale would be a useful screening device with outpatient populations. Possibilities for future research were discussed.Psychology, Department o