What countries have "gone all in"? In everything I've read, many are looking into it and trying to understand how it might work, and some studies show that it may have promise in treating some of the symptoms. But others remain skeptical and point out, as any responsible scientist would, that this is all very preliminary and that there simply hasn't been enough study on this to make any conclusive determinations at this point.

So show me which countries (cite sources, please) are "going all on" on this, and just what exactly that even means.