P: Ellis claimed a 90% success rate for REBT, taking an average of 27 sessions to complete the treatment.
E: REBT have done well in outcome studies of depression . a review by Cuijpers of 75 studies found that CBI was superior to no treatment. Ellis recognised that the therapy was not always effective, and suggested that this could be because some clients did not put their revised beliefs into action.
L: This suggests that REBT is effective, but other factors relating to both client and
therapist may limit its effectiveness.