A huge study finds a link between cannabis use in teens and psychosis later

Researchers followed more than 400,000 teens until they were adults. It found that those who used marijuana were more likely to develop serious mental illness, as well as depression and anxiety.
(Image credit: Justin Sullivan)
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Left: USA's Ben Ogden competes during the cross-country free sprint on Wednesday. Right: Bronze medallist USA's Jessie Diggins celebrates on the podium for the women's cross-country 10km. Both Olympians knit during their downtime between events.'/>













