The Substance Use Motivation Ruler is an excellent tool derived from motivational interviewing. Ask your client to pinpoint, on a scale of 1 to 10, how motivated they are to end their drug use. In this case, 1 means "not at all motivated" and 10 means "completely motivated".
In the spirit of motivational interviewing, you want to use this worksheet to build congruence, and focus on what motivates the client. If they respond with a 4, ask them: "What led you to choose 4 rather than a 2 or a 3?". You can also ask: "What would have to happen for you to move from a 4 to a 5 on the scale?"
1. Miller, W. R., & Rollnick, S. (2002). Motivational Interviewing: Preparing people for change, (2nd ed.). New York, NY: Guilford Press.