In 2009, a 25-year-old North Korean man escaped the country, swimming across the Tumen River.

Speaking to The Wall Street Journal, he said, “I inhaled about ten hits before I went to the river. I felt really focused, all I could think was go, go, go. I didn’t sleep for two days after that.” He now lives in Seoul and did not want his name revealed, presumably fearing reprisal from the regime. From WSJ:

Before his defection to South Korea, he says he used the drug, known as “bingdu” or “ice” in the North, off and on for about three years. He says it was easy to score, dealers worked the streets of his hometown of Hamhung, South Hamgyung Province. … As for the 25-year-old defector, he says he never felt addicted to ice and looks back fondly on his experiences getting high with his friends in the North. But like many other things he’s left behind, that aspect of his life stopped at the border.

A 2013 study in a North Korean science journal confirms the prevalence of methamphetamine use. Kim Seok-hyang, a co-author of the study, estimates that 40-50% of adults in North Korea use crystal meth.

Crystal meth use has been growing there since the 1990s. From Business Insider:

Opium was once the North Korean drug of choice, but the fields dried up in the middle of the last decade. But now meth is being embraced. In March, a report alleged an unknown number of North Korean diplomats were given about 44 pounds of illegal drugs to sell on trips abroad. (Including a diplomat in at least one Eastern European country!) … Meth use has apparently become so widespread that Kim Jong Un tried to enforce a crackdown on meth use in the northern parts of the country almost two years ago. So far, it doesn’t seem the effort was effective.