Its not a bug and intended to stay permanent, you need to clear it with certain item.
Viewing post in [Bug Report] Permanent Overdose
Same here, it's torture. I'm playing on normal and regret it already so so much. I played 7 houers and get my ass beaten by some annying wann be easter egg boss... it's simply terrible for me. I tried to cheat bt no way the interface on saveeditor is so messed up its not possible to turn you dmg to the max..... I don't understand why games like these have to be so hard these days it's still some kind of fetish game so in my opinon its not necessary to create a fear and hunger light clone.... :(