Prolonged abuse of nitrous leads to B vitamin deficiency, which leads to severe nerve damage. It takes a lot of nitrous, but it can be veeerrrry addictive. Someone left alone with a whole tank to themselves for a week can really fuck themselves up.

nitrous oxide depletes it in the body. B-6 and B-12. prolonged useage can cause nerve damage because of that depletion. otherwise it's a safe gas as long as you make sure to include oxygen