Selecting a Control Group

A private corporation has obtained government funding to test dramatic enhancements in a program that treats addiction to painkillers.  Owing to the nature of the psychological interventions used, subjects who were exposed to the older program might or might not respond well to the enhancements.  Is it appropriate to use the old program with a control group, when testing effectiveness of the new program?  Would it be appropriate to use the old program with a control group, when testing whether exposure to the old program reduces effectiveness of the new program?