| Abstract: | ABSTRACT— The phrase primum non nocere ("first, do no harm") is a well‐accepted credo of the medical and mental health professions. Although emerging data indicate that several psychological treatments may produce harm in significant numbers of individuals, psychologists have until recently paid little attention to the problem of hazardous treatments. I critically evaluate and update earlier conclusions regarding deterioration effects in psychotherapy, outline methodological obstacles standing in the way of identifying potentially harmful therapies (PHTs), provide a provisional list of PHTs, discuss the implications of PHTs for clinical science and practice, and delineate fruitful areas for further research on PHTs. A heightened emphasis on PHTs should narrow the scientist–practitioner gap and safeguard mental health consumers against harm. Moreover, the literature on PHTs may provide insight into underlying mechanisms of change that cut across many domains of psychotherapy. The field of psychology should prioritize its efforts toward identifying PHTs and place greater emphasis on potentially dangerous than on empirically supported therapies. |
