Non-diagnostic psychotherapy is a way of constructing therapy that does not follow the method used commonly by medical doctors (the medical model) of first diagnosing and then engaging in a prescribed treatment approach based on that diagnosis. Instead, psychotherapists who work non-diagnostically relate to patients holistically, understanding that suffering, while serious and painful, need not be understood only in prescribed ways. Further, non-diagnostic therapists relate to all patients as unique and therefore do not assume that one can make decisions about how to help someone who is suffering based solely on a category or categories of suffering (i.e. diagnosis).
For us, practicing non-diagnostic psychotherapy necessarily demands creativity on our part, as well as on the part of our patients. Why? Because if we're not going to limit our work to following the prescription (i.e. the DSM-V and related "standards of practice"), we're going to have to forge our own path--in other words, we're going to have to create our own tools for growth and happiness. This is both a tremendous challenge and an opportunity; we can create tools that aren't defined by others and we can get better at the activity of creating tools itself.