Designing a control for a behavioral group therapy.

To evaluate whether the specific techniques of a newly developed behavioral therapy exceed the effects of its common factors (e.g., therapeutic alliance), an ideal comparison control must omit the unique ingredients of the active treatment while possessing the common factors in equal measure. Reviews of the controlled-trial psychotherapy research literature show that such systematic matching is not a common practice. Addressing this gap between theory and practice, we delineate 7 steps for designing a credible control for a recently developed behavioral therapy adapted for binge eating disorder--dialectical behavior therapy (DBT). Our detailed description of matching the common factors to the extent possible and specifically measuring these offers a useful research design template for investigators of controlled behavioral treatment trials.