Despite efforts to reclassify marijuana down to a Schedule II (read: less dangerous) drug, there are some people who still insist on its dangers—and new research may back those theories up. Scientists at King's College London have discovered that smoking potent, or "skunklike," cannabis was tied to almost a quarter of all new psychosis cases they studied, the BBC reports. The study published in the Lancet compared 410 patients between the ages of 18 and 65 who had experienced "first-episode psychosis" with 370 healthy patients. The results suggest that the development of psychosis—i.e., delusions and hallucinations—is three times greater for skunk smokers than for nonusers, and up to five times higher if they smoked it every day. Hashish, a milder form of cannabis that contains much less THC than the skunk variety, isn't linked to any increased risk for psychosis.
English experts say that skunk cannabis is widespread, with one doctor telling the BBC, "In London, it's very difficult to find anything else." Anecdotal stories that back up the study's warnings are worrisome. One woman tells the BBC that, after smoking skunk pot, she "went from someone who had never experienced any mental health issues whatsoever to an absolute wreck." A recovering addict who's now a drug counselor tells Sky News that skunk is the "Incredible Hulk of cannabis [and is] absolutely decimating young people's lives." Still, despite the warnings, study researchers point out that, according to a 2010 study in the Lancet, the three most harmful drugs are alcohol, crack cocaine, and heroin; cannabis falls at No. 8, notes Channel 4 News. (It's not the first time suspicions have been raised linking skunk cannabis to psychosis.)