The best remedy to treat cannabis psychosis is legalization, according to a researcher who recently pored over 50+ years of studies on marijuana and mental health. University of York lecturer Ian Hamilton says that the incidence of cannabis users experiencing psychotic episodes is relatively low, but the best way to reduce the number of those incidents even further is to legalize and regulate marijuana.

Cannabis psychosis occurs when exposure to tetrahydrocannabinol (THC) triggers psychotic symptoms in consumers - especially those with schizophrenia and teenagers, whose developing minds are particularly susceptible to the potential risks of cannabis use. But even then, the incidence of cannabis psychosis is still rare, according to Hamilton.

"The link between cannabis and psychosis has been investigated by researchers since the drug became popular in the 1960s," Hamilton told The Independent. "A new review of research carried out since then has concluded that ‘at a population level the increased risk is weak and the vulnerabilities relatively rare'. To put this in perspective we would need to prevent 23,000 people using cannabis to prevent one case of psychosis."

That means you have much better odds of bowling a perfect game, dying in a car crash, winning an Academy Award, or being born with extra fingers or toes than experiencing cannabis psychosis.

But Hamilton added that cases of psychosis could be on the rise since the potency of today's marijuana is much stronger than the weed researchers studied back in the 60s. And higher concentrations of THC mean a higher potential for a psychotic episode.

“Most of the seminal studies on this link were carried out when people were using lower-potency cannabis,” he said. “Few studies have been conducted since the emergence of higher potency cannabis sometimes referred to as 'skunk’. Higher potency cannabis contains less cannabidiol (CBD), which is believed to offer some protection from developing problems such as psychosis, but higher levels of tetrahydrocannabinol (THC) which can trigger psychosis.”

To diminish those risks, he recommends legalizing marijuana. That way, consumers can buy quality-controlled cannabis products in packages with warnings about the product's potency.

“This would provide users with information about the strength of cannabis on offer, something they usually only discover after exposure in the current unregulated market,” Hamilton added.

So the best way to make cannabis safer is to get it off the streets and put it on the shelves of retail stores.