[luesterklemme]

The "reverse" effect would be a Nocebo. Which also exists. https://en.wikipedia.org/wiki/Nocebo

[zigzag312]

Thanks, that's a more accurate reverse effect to placebo.

I was thinking in a wider sense, negative effect of mind on health instead of positive. It's intriguing to what extent it's speculated the mind is able to affect the physical health.