Several authors have recently argued that psychotherapy, as it is commonly practiced, is deceptive and undermines patients’ ability to give informed consent to treatment. This ‘deception’ claim is based on the findings that some, and possibly most, of the ameliorative effects in psychotherapeutic interventions are mediated by therapeutic common factors shared by successful treatments, rather than because of theory-specific techniques. These findings have led to claims that psychotherapy is, at least partly, likely a placebo, and that practitioners of psychotherapy have (...) a duty to ‘go open’ to patients about the role of common factors in therapy ; to not ‘go open’ is supposed to unjustly restrict patients’ autonomy. This paper makes two related arguments against the ‘go open’ claim. While therapies ought to provide patients with sufficient information to make informed treatment decisions, informed consent does not require that practitioners ‘go open’ about therapeutic common factors in psychotherapy, and clarity about the mechanisms of change in psychotherapy shows us that the common-factors findings are consistent with, rather than undermining of, the truth of many theory-specific forms of psychotherapy; psychotherapy, as it is commonly practiced, is not deceptive and is not a placebo. The call to ‘go open’ should be resisted and may have serious detrimental effects on patients via the dissemination of a false view about how therapy works. (shrink)