Does anyone know about studies that compared a combination of cognitive defusion and cognitive restructuring, with cognitive restructuring alone, and/or with cognitive defusion alone, regarding their effects on believability of targeted thoughts?
I'm not aware of any existing study that actually attempts to combine the two, as you suggest, but I have had an interest in doing one for some time! Specifically, I have some hypotheses about which types of patients would benefit more from starting with restructuring and then proceeding to defusion, versus just going straight to defusion. Why do you ask? Are you interested in potentially collaborating on this? :)
I don't think there's necessarily a conflict at the level of technique and I think it's necessary to pick a foundation as to the rationale. Is believability your end goal, if so, what is the purpose of impacting on that? I have some Relational Frame Theory ideas about that.