Send to

Choose Destination
Epidemiol Psychiatr Sci. 2016 Oct;25(5):428-435. Epub 2015 Sep 28.

How to prove that your therapy is effective, even when it is not: a guideline.

Author information

Department of Clinical Psychology,VU University Amsterdam,The Netherlands.
Department of Clinical Psychology and Psychotherapy,BabeĊŸ-Bolyai University,Cluj-Napoca,Romania.



Suppose you are the developer of a new therapy for a mental health problem or you have several years of experience working with such a therapy, and you would like to prove that it is effective. Randomised trials have become the gold standard to prove that interventions are effective, and they are used by treatment guidelines and policy makers to decide whether or not to adopt, implement or fund a therapy.


You would want to do such a randomised trial to get your therapy disseminated, but in reality your clinical experience already showed you that the therapy works. How could you do a trial in order to optimise the chance of finding a positive effect?


Methods that can help include a strong allegiance towards the therapy, anything that increases expectations and hope in participants, making use of the weak spots of randomised trials (risk of bias), small sample sizes and waiting list control groups (but not comparisons with existing interventions). And if all that fails one can always not publish the outcomes and wait for positive trials.


Several methods are available to help you show that your therapy is effective, even when it is not.


Control groups; randomised trial; researcher allegiance; risk of bias


Supplemental Content

Full text links

Icon for Cambridge University Press
Loading ...
Support Center