Is marijuana linked to psychosis, schizophrenia? It's contentious, but doctors, feds say yes

Early one morning in March, Madison McIntosh showed up on his day off at the Scottsdale, Arizona, driving range and restaurant where he worked. The 24-year-old sat in his car until the place opened, then wandered around all day, alternating between gibberish and talk of suicide as co-workers tried to keep him away from customers.

When he was still there 12 hours later, the manager contacted McIntosh’s father in Las Vegas, who called police and rallied other family members states away to converge at the young man’s side.

They found...