@vital
I see evidence based medicine coming is three forms. A commonly wide spread agreed upon fact, or there is enough evidence now that we think this might be true, or there is just not enough evidence to say anything conclusive about this or that. All taking place after much debate research and study.

This would be among the medical community at large and include the best institutions in the world who study it. For example- John Hopkins, Stanford, Harvard, Oxford, the best teaching hospitals like Mayo, U of M, the Cleveland Clinic, or NIH and NIMH, the CDC, WHO, etc. The combined body of knowledge from the best possible sources in the world published in the best journals. Not the opinions and claims of one doctor here or there. Dr. Oz just got called to the carpet on claiming that green coffee bean extract was a miracle cure for something or other. He based his claim on one 17 person study in India paid for by the company that makes the extract. A recent study said that half his claims have no evidence whatsoever and he is a doctor. Claims have to be backed up by a large body of scientific evidence to be viewed as true.

Advising people on medication is a big deal and in my opinion should be based on the best currently available information backed up by the best reliable sources and studies and looking at the whole body of knowledge. Not one or two initial clinical trials or the views of one doctor or another. Not a whole lot is known about any medication that has ever hit the market until it has been out in the real world for some time and follow up studies are done. Many psyche meds have been on the market for a long time and much is known and much is unknown. If it is unknown we have to say we just don't know that yet.