I think evidence-based with regards to psychology is highly overrated. Insurance companies and other entities like the NHS push evidence-based treatment because it's usually time-limited and will cost them less money. I think in theory it's good to pursue evidence that a treatment is effective, but there are limitations to the way these studies are set up and executed. There have also been studies that show that the effectiveness of evidence-based treatment is not always and perhaps quite frequently not long-term.

I think proving something in psychology is an entirely different beast than proving something in other scientific fields and if you're waiting for proof, you may be waiting a long time.