Three experimental psychological tests were investigated to determine if they added significantly to the prediction of eight drug abuse criteria when combined with a basic predictor set consisting of background variables only. Of the four tests investigated, only one, the Life Values Questionnaire appeared to add any significant unique variance to prediction when combined with the background variables. In addition, the inclusion of the LVQ with this basic predictor set resulted in significant multiple validities for all the criterion variables except Heroin, Barbiturate and Miscellaneous Abuse. Even though the LVQ does not by itself yield high validities for any of the eight drug abuse criteria, it does have considerable success in discriminating between drug abusers and nonabusers. (Author)