Lancet: cannabis multiplies psychosis risk x 5, weekend use x 3

2/16/15–In Lancet Psychiatry, healing a team of 23 scientists published a large study showing that people who smoked high-grade marijuana – about 16% THC with no CBD, similar to average US varieties of marijuana – were five times as likely than non-users to have a psychotic disorder. Weekend users were three times as likely than non-users to have a psychotic disorder, and high potent marijuana use alone was responsible for 24% of those adults presenting with first-episode psychosis to the psychiatric services in south London. Read