The issue of mistakes seems of more concern to therapists than to patients. Therapists have to grow to recognize that the world of their profession is not based on eternal verities. They must learn that they are not always right, nor need to be, about their understanding of the patient’s world. As D.G. Edwards advises, one should not even aim to always be right. Having a predetermined fixed response or role ― imposing a strict standard or rigid rule for a presumably perfect therapeutic word or deed ― is neither possible, nor advisable. Thus in the matter of mistakes in psychotherapy, it is not even preferable to be too correct. A grain of wrong actually belongs to good taste, says Nietzsche.
The process of psychotherapy involves oscillations in small increments between “getting worse” and “getting better,” between failures and mini-successes. No treatment is ever a total failure, as it is joked; it can always be used as a bad example. More seriously, if every gesture were thoroughly rehearsed against making mistakes, it might give an impression of spontaneity, but it would not really be. Furthermore, it would be exhausting and ultimately ineffective.
Ironically, some of the negative repercussions of psychotherapy come from its effectiveness, insofar as collective reviews of research have typically shown greater variability of outcomes in treated than untreated groups. They have even shown that a proportion of treated patients get worse. H.H. Strupp and colleagues were more specific in their findings that personality characteristics of the clinician impacted upon therapy effectiveness. Qualities such as coldness, hostility, seduction, pessimism, and narcissism of the therapist contributed to negative outcomes, as well as having an inappropriate goal or goals for the patient, fostering overdependence, and breaching confidentiality.

