Canada’s marijuana consumers — medical and recreational — may do a little dance of joy come Oct. 17 when our nation becomes the first major, industrialized nation to legalize cannabis.
Undoubtedly, their past experience means they’re ready to consume the product that will be offered at retail outlets in Manitoba and online.
Yet for a significant number of adults, trying cannabis will be a novel experience — or at least one they haven’t embarked on in many years. With that in mind, here’s a primer on its effects on mind and body. That way, a mind-bending adventure are less likely to result in a bad trip.
First things first: Cannabis is relatively safe compared with other psychoactive substances, including alcohol, according to a 2015 comparative risk study. There has not been a clear-cut, documented death from an overdose of cannabis.
Still, cannabis may pose higher risk of adverse outcomes for individuals with mental illness and cardiovascular disease, cautions Daniel Sitar, a retired University of Manitoba professor of pharmacology.
One reason for cannabis’s relative safety is it doesn’t depress the respiratory system like opioids do, says Sitar, who runs seminars on cannabis’s interaction with other medications.
"Morphine, fentanyl and similar drugs can kill you by stopping your breathing," says the professor emeritus at the Rady Faculty of Health.Advertisement
"THC, in fact, does not involve much respiratory depression."
THC, or tetrahydrocannabinol, is what delivers cannabis’s high. It’s one among dozens of cannabinoids present in marijuana that include cannabidiol, or CBD — which is gaining a reputation among medical users for a variety of beneficial effects, including easing anxiety.
Why THC intoxicates is still a work in progress for researchers, Sitar notes. What we do know is it works on our body’s endocannabinoid system.
"As far as I understand right now there is good evidence for two cannabinoid receptors that are affected," he says, adding further research could reveal more.
One receptor called CB1 — found in abundance in the brain — is associated with getting high. The other, CB2, has some effect on immune response, among other functions, but it is not thought to elicit psychoactive effects.
Normally these receptors interact with our own "homegrown" cannabinoids called anandamide, a neurotransmitter sometimes referred to as the ‘bliss molecule.’ It helps regulate mood, memory, motivation, thought processes and appetite. Like anandamide, THC binds to the same receptors — generally for much longer — potentially affecting all these areas.
Effects can vary from person to person, Sitar says, because our neurochemistry is a "complex soup" with many ingredients working together at once.
"All these different neurotransmitters — acetylcholine, anandamide, norepinephrine (adrenaline) and endogenous opioids — interact with each other," he says.
Adding an outside substance can lead to a "variety of possible outcomes."
That’s why one person may find cannabis pleasurable while another feels anxiety. Sitar says a person’s mindset, physiology and past experience can affect the outcome.
Also critical is the strain of cannabis ingested — and there are hundreds — with varying THC content.
Generally speaking, the higher percentage of THC in a strain of cannabis, the higher you feel. That’s why cannabis educator Marshall Posner with Manitoba’s leading licensed producer of medical marijuana, Delta 9 Cannabis, recommends neophytes "start low and go slow."
By ‘low,’ try a strain "with about 10 to 12 per cent THC," says Delta 9’s vice-president of sales and marketing. (The high end for THC content is 20 per cent or more.)
And ‘slow’ refers to "taking a couple of puffs on a joint." Even better, use a vaporizer that delivers the psychoactive ingredients without combusting plant matter, which can release toxic chemicals. Another tip, he suggests trying a strain with high CBD, which he says helps curb anxiety. Additionally, users are increasingly focused on terpenes, chemicals that make up the odour of cannabis, which are believed to modulate the high from one strain to the next.
Regardless of choice, wait before trying more. Posner says the effects, when smoking, are felt within about five minutes. But it can take 15 minutes or more to feel the effects fully.
When inhaled, the most intense sensations last about an hour — though residual effects can last up to four hours. The high is even more long-lasting when cannabis is ingested. Although edible products are not legal for sale, users can make their own. Cannabis-infused oils can be ingested or added to food.
But don’t eat raw cannabis; you’re likely not going to get any effect because THC needs to be heated and bonded with a fat so it can pass into your brain, Posner says.
Furthermore, Posner says tread lightly with edibles. Novices often unintentionally over-indulge.
"They don’t realize it can take 60 minutes or more before effects begin, so after 30 minutes they say ‘I don’t feel anything. Give me another brownie.’"
Then they have a "bad episode."
Should that occur, don’t fret (or try your best not to).
"Keep yourself distracted," he says. Listen to music; watch a movie; take a walk, and eat a snack.
Just don’t drive. The rules of thumb regarding how long to wait before driving are still being worked out, Posner says.
"We tell our medical patients not to operate a motor vehicle... four to six hours after smoking... and 10 to 12 hours for edibles."
Occupational health nurse Darcy Hansen, who works with a Lethbridge, Alta., company focused on cognitive-performance drug-testing software for the workplace, says Canada’s new impaired driving laws for cannabis are a "can of worms."
The president of Healthyworker.ca explains excess THC is stored in your fat and can get released into the bloodstream over time, especially for frequent users. "So even if you’ve abstained for a couple of days, good science shows you could still be over (the limit)."
Driving with just two nanograms of THC per millilitre of blood can lead to a $1,000 fine. And more than five ng/ml is a mandatory $1,000 fine and up to 30 days in jail.
A blood-alcohol level of 0.05 per cent, or 2.5 ng/ml is all you need for a $1,000 fine and possible jail time. "This is a huge concern for anyone consuming cannabis," he says.
Sitar says determining intoxication levels for cannabis is likely to be a key focus of research for cannabis in the next several years.
More broadly, he adds, if there is one upside to legalization most can agree on, it’s that it should lead to better scientific evidence.
"Because the drug has had such a bad reputation put on it by the governing bodies in the world, we’re only now going to be able to study it in much greater detail," he says. "This is an area should explode in the next decade."