An emergency psychiatrist in Victoria warns that a dramatic increase in severe mental illness cases may be connected to use of a powerful, relatively new drug called "shatter."

Dr, Kiri Simms told On the Island host Gregor Craigie she treated 10 patients needing hospitalization in the past year after using shatter or other highly concentrated marijuana-based products made from butane hash oil.

"They're coming in with symptoms of depression, anxiety and sometimes psychosis, which for a psychiatrist means a break from reality, hallucinations, delusions," Simms said.

Marijuana psychosis previously rare

In the past, when most marijuana use involved smoking dried leaves and buds, she said the infrequent cases of marijuana-related psychosis usually were patients with a family history of schizophrenia.

"Most people did not become psychotic from marijuana alone." Simms said.

Several medical marijuana stores in Victoria openly advertise shatter and related marijuana products which an emergency psychologist links to an increasing number of cases of severe psychosis. (CBC)

That has changed. Now, most of the patients she currently sees are regular users of different marijuana products, often what she calls butane hash oil products. Those include shatter, wax and a gooey substance called honey or butter or oil, she said.

Simms said she has personally seen 10 people in the past year, "very, very ill and with the kind of psychotic experience that requires a stay in our psychiatric intensive care or on one of our in-patient wards."

She said it's not like the 'old days' when symptoms of psychosis would pass in a few hours or days.

"Now, sometimes it's taking weeks before there is a clearing and occasionally it's taking months and the patients are not cleared yet," Simms said.

"Almost all of our patients, even our young patients tell us they can easily obtain these products in the local dispensaries."

Shatter is openly advertised online by a number of medical marijuana storefront businesses in Victoria.

Dana Larsen, the director of the Vancouver Dispensary Society, acknowledged that products such as shatter are too strong for inexperienced users but he does not support new rules or regulations for selling it.

"I think perhaps there should be better labelling and warnings on how to use cannabis products," Larsen said. "I don't think this is inherently more dangerous than other cannabis products."

To hear the full interview go to: A psychiatrist warns about the dangers of shatter.