For whatever reason when you're addicted to a drug it will have a period where it bugs out and tells you that you need a fix even after taking 3 hits in a row. You then get a rather absurd series of nonsensical will saves that takes up your combat log. Both are not the best thing for a lonely wizard wandering lower dark!
I've only experienced this with my slimesquat addiction, thank God not substance...
Oh it happens with substance too.