ABUSE LIABILITY ASSESSMENTS IN HUMANS - M ETHODOLOGICAL ASPECTS

Different methods have been developed in clinical abuse liability test ing in man. Tolerance, psychic and/or physical dependence must be inve stigated through clinical studies during drug development of a new sub stance. Adequate methodology is needed using double-blind, time-blind evaluations, comparisons of different dose levels and duration of trea tment for a given drug, abrupt and gradual interruption of treatment, appropriate period of observation after treatment cessation... The opt imal scale to evaluate properly the symptoms occurring after drug disc ontinuation is still under investigation. These studies will or should permit the differentiation of rebound, withdrawal and recurrence. Met hods developed to study reinforcing effects in post-addicts and health y subjects are self-administration and choice procedures. In addition, the more traditional approach has been through assessing self-reporte d effects in which standardized questionnaires are used (Addiction Res earch Center Inventory or A.R.C.I.; Single Dose Questionnaire or S.D.Q .). A third focus of measurement has been discrimination studies perfo rmed in individuals with histories of drug abuse as well as healthy su bjects. Abuse-liability testing of a new compound needs a multidimensi onal assessment to optimize the predictivity in defining the relative risk.