Internal Family Systems Therapy looks at our brain and all of its sub parts as a whole. Our brains are made up of lots of different parts that make up our personalities and urges and they all cooperate to make up yourself.
As of now, IFS Therapy has been shown to be effective at reducing symptoms of depression,  but there is no data on whether or not IFS Therapy is effective for treating DPDR. However, the idea behind addressing and accepting all parts of the self is sound and it may be worth exploring if other methods have not alleviated symptoms.
An issue with traditional talk therapy is that clients come in intent on changing, rather than accepting, their unwanted behaviors, emotions, or thoughts. However, the problem is often that their lack of self-acceptance is the primary obstacle to change. The Internal Family Systems (IFS) model, fosters clients’ acceptance of all parts of themselves no matter how destructive, and how that acceptance can lead to the transformation of those parts and, in turn, of other people.