Yes, just as the very strict Iran has a huge heroin problem, the totalitarian state of North Korea has developed a meth problem, though for different reasons:
Here, you have the 'blowback effect' of people who got into it because they were making it for the government. The real problem there is that life is so miserable that getting hooked on a first try is almost a bygone conclusion. The 40-50% northeast provincial addiction rate sounds a little high, but North Korea is such a bizarre place, who knows what is really going on.
The worst part is that no one there will get any form of treatment except by firing squad.