Solarpunk

There is the big risk in having, and assuming, a society where some particular evil doesn't exist. Namely, that when evil does actually appear, the society will be completely defenceless. Whether it's disease or crime or some other problem.

I think that in general there needs to be both preventative hygiene/education/culture and some form of cure/resistance/response available to counter problems. And even then, there will be no absolute protection.

First requirement for either would be research and understanding of the threat and development of methods and mitigations. Then taking them into widespread use. With mental health, these are all somewhat under way, but probably lagging behind the more "low level" biology.