Geriatrician Jennifer Watt opened the elderly man’s file. She was doing a follow up appointment with him after he’d come to an emergency room with delirium, a type of confusion that’s common in the elderly, and been admitted to the hospital. The notes said the issue had resolved itself, and it wasn’t clear what set it off. “There are lots of different risk factors for delirium, and he had things that would put him at risk,” she explains. But the trigger was unclear – until they started discussing his drug use.
He’d been looking for pain relief, and sought out some marijuana himself. “He began taking it, and got confused,” she says. “He was very honest with me when I asked. It was just that no one had asked before.”
Gabriella Gobbi, a professor of psychiatry at McGill University and psychiatrist at McGill University Health Centre, says she’s also seen several elderly patients with delirium caused by cannabis use.
We often hear about the potentially negative health effects of marijuana on young people, especially on developing adolescent brains. But some doctors, like Watt and Gobbi, believe we need more research on its effects on the elderly. They are concerned that we don’t know enough about its potential side effects, including confusion and an increased risk of falling.
Many seniors use cannabis for medicinal reasons, including pain and insomnia. Medical marijuana has been legal in Canada since 2001 – some dispensaries even offer seniors’ discounts. And its use is on the rise, with almost 130,000 Canadians registered to purchase it as of 2016, up from 7,900 in 2014. General use may also rise as the federal government moves to legalize marijuana by July 2018.
The elderly are significantly less likely to use marijuana than the regular population. But as cannabis becomes more generally accepted and aging Boomers hit retirement, more seniors may use it in the future. The U.S., which has legalized marijuana in eight states, has seen a rise in cannabis use in people over 50: in 2006/07, three percent of people in that age bracket said they’d used marijuana in the past year; in 2012/13, that number rose to five percent.
“It’s use has become a very important issue,” says Gobbi. “More regulated research must be done in the elderly, to understand how cannabis can be used in this vulnerable population without side effects.”
The health effects of cannabis
There has been quite a bit of research into the health effects of marijuana in general, with more than 60 systematic reviews on the subject. Some studies have found it can help with treating nausea and vomiting from chemotherapy, reducing spasticity from multiple sclerosis, helping with Tourette’s syndrome, and reducing sleep disorders, though the evidence tends to be mid- to low-quality and vulnerable to bias. Cannabis is also often used for pain reduction, but the evidence around that is mixed.
There are some negatives: marijuana may increase the risk of testicular cancer and some mental health problems and it’s not safe during pregnancy. There have also been studies that suggest cannabis might be associated with problems like depression, anxiety, bladder cancer, bone loss or brain changes, among others, but the evidence around all of this is still inconclusive.
Elderly people may have distinct risks: A 2014 review on marijuana and older people pointed out that drowsiness and dizziness were two known side effects of marijuana that could contribute to falling in older people. It also pointed to an increased risk of arrhythmia.
Other studies have shown that marijuana might trigger a stroke in people with coronary artery disease. Marijuana’s cognitive effects could have a larger impact on older people who are already struggling cognitively. And cannabis can cause side effects when mixed with other medications, such as increasing the risk of bleeding, lowering blood pressure, and affecting blood sugar levels.
It’s difficult to research marijuana in the U.S., where it’s classified, federally, as a Schedule 1 narcotic. It’s much easier to do studies on it in Canada, but it still hasn’t gone through the same rigorous process as a regular pharmaceutical drug would have. “Cannabis took this strange pathway,” says Gobbi. “I think that cannabis should go through clinical phases, as all drugs do, which would include testing on the elderly population.”
Effects on the elderly
The vast majority of cannabis research is done for the population in general and either doesn’t include the elderly at all or doesn’t report on them separately. A 2014 editorial in the Journal of the American Geriatrics Society made the argument that we need more research on the elderly and pot, as they’re likely to have adverse effects that are specific to them.
Mona Sidhu, a geriatrician who works out of Hamilton Health Sciences, knows this issue well. She routinely prescribes marijuana for seniors, mostly for pain management in people without cancer. “I fell into this,” she says. “I was asked to see patients that would be potential candidates for cannabis use, and having very little background knowledge, I didn’t know the potential.
“I learned from some other physicians, and after trying it on some seniors, and seeing how their fentanyl and morphine use started to reduce, I started prescribing it more.” She says it has helped many of her patients manage their pain, sleep better, and reduce anxiety.
She does start seniors on a lower dose than she uses for other people, she says, in the same way as she would modify the dose of a pharmaceutical drug. She also recommends seniors use a vaporizer or oral dose. She’s swayed by her personal experience, and by the anecdotal research out there supporting it. “Even though the high quality data is not out there, we should not ignore the anecdotal evidence that supports the use of marijuana,” she says.
Brian Kaskie, a researcher at the University of Iowa and the author of a 2016 paper that looked at the trends around marijuana usage in seniors, agrees. His paper pointed out that more older adults are using cannabis, and many of them are using it for medicinal reasons, and in place of prescription medications. While he acknowledges that may lead to some side effects, like falls, he’s excited about the possibility it brings, too. Many of these issues, like pain, “aren’t as relevant to people under 50,” he says. “The potential here is compelling.”
Fiona Clement, director of the Health Technology Assessment Unit at the University of Calgary and co-author of a review of the evidence around cannabis, looks at it differently. “If we held marijuana to the same standards as the other drugs we allow on the market, I don’t think it would meet the bar [for effectiveness as a treatment],” she says.
And everyone agrees that the evidence around all of this is still hazy. As Watt says, “At the end of the day, when it comes to knowing the potential benefits and harms and having that conversation with patients, right now we’re quite hindered by the lack of evidence.”