The Personal Drug Use Questionnaire is a 19 items self-administered questionnaire and its primary use is to assess readiness for change in drug users. These instruments (SOCRATES, in its different forms) can be used as useful research instruments to assess readiness for change in clinical substance user populations.
Various other forms of the SOCRATES have been developed.
Version 8 is a reduced 19-item scale based on factor analyses with prior versions. The shorter form was developed using the items that most strongly marked each factorand is currently the recommended version.
Miller, W. R., & Tonigan, J. S. (1996). Assessing drinkers' motivation for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES), Psychology of Addictive Behaviors, 10(2), 81-89.