Researchers are sounding alarms over young people smoking cannabis, as the incoming government promises a referendum on legalising the drug.
A paper presented to the World Psychiatric Association in Berlin shows teenage pot smokers are likely to develop schizophrenia 10 years earlier, than others with a predisposition to the illness.
It also suggests a link between the amount of dope they smoke and how early the onset is.
Tauranga drug addiction worker Darryl Wesley said it's definitely something he's seen on the job.
"The guy I'm thinking of he would have been 21 and those symptoms probably started for him maybe a year prior to that, and he was quite a heavy cannabis user yeah, he kind of grew to accept that if I hadn't done this I might not be struggling so much now."
Wesley said it's tragic to see young people affected by the disease after smoking pot.
"We came across younger people say 17, 18,19 who had developed symptoms of schizophrenia because of potentially their marijuana use."