© The Canadian Press/Tijana Martin Cannabis harvested at the CannTrust Niagara Greenhouse Facility in Fenwick, Ont., is photographed on June 26, 2018.
"Just because it's legalized, does not make it safe," was the way Dr. Serge Melanson put it on Wednesday in Moncton.
That's the message the president of the New Brunswick Medical Society said he wants to be emphasized as the era of legal recreational cannabis in Canada begins on Oct. 17.
With consumption rates "likely" to rise, it's important that potential users are aware of the potential physical health and mental-health problems associated with consumption, Melanson said.
"Right now, we recognize patterns where patients are turning to cannabis to self-treat for problems like depression and anxiety. My own experience as an emerg physician is that tends to worsen and compound their problems so we may see that phenomenon at a greater degree," he said.
"We're about to take on a major sociological experiment in this country."
There is added concern for certain people, including pregnant women, who are advised not to consume it.
The same goes for young people, whose brains continue to develop into their mid-20s; cannabis can trigger issues associated with mental illness, he said.
Driving while high is another major concern, especially because it can impact not just the person behind the wheel.
There are also the lesser-known potential problems.
"It's called cannabis hyperemesis syndrome," Dr. Ryan Sommers, the regional medical officer of health for Nova Scotia Health Authority's northern region, described in a Skype interview from Truro, N.S.
"It can cause, for a small portion of the population, uncontrollable vomiting, and we see that more commonly in people who are chronic users."
Also, it's harder to determine how long someone will be impaired by cannabis versus being impaired by alcohol, he said.
Both doctors said the key is for people to be informed of the health impacts of cannabis. The New Brunswick government's website and the Nova Scotia government's website provide links for more information.