As legalization efforts continue in many states, experts weigh in on the significance
Less than 50 years ago—1970, to be exact—the United States Congress declared marijuana a Schedule I substance in the Controlled Substances Act, indicating that it had “no accepted medical use.”
It wasn’t until 1996 that this ruling was challenged in any legislative manner, when the state of California legalized marijuana for medical use only, meaning individuals needed a prescription to receive the drug.
The floodgates would open after the turn of the century, bringing us to a point where 29 states now allow the use of marijuana for medical purposes—while nine others allow recreational use. Turning this into a state issue has done little to slow down the debate either, as advocates argue for the medical benefits and detractors point to what they feel is a lack of evidence. Does one side have a stronger case than the other?
Brad Gillespie, PharmD, lived in California for a time following the state’s legalization of medical marijuana only.
“I don’t know that people should employ the medical argument for legalization unless they can prove that it safely works,” he said. “To date, no one has done so.”
The debate has taken on added importance in the past couple years as the opioid epidemic gains steam. If one of the main benefits of medical marijuana use is pain relief, as many claim, could it be the solution to the problem?
“It’s awfully controversial,” Dr. Gillespie cautioned. “I have seen one interesting piece that looked at opioids and medical marijuana use from 1999–2010.”
That piece concluded that states with legal medical marijuana saw a rate of opioid-related deaths 25 percent lower than that of other states. “Now, that doesn’t prove anything,” Dr. Gillespie said. “There’s no cause-and-effect that can be established there. It’s just an interesting finding.”
Other controversy in this area involves an idea some have floated of directly treating patients with opioid addictions via medical marijuana. “Some people think it’s great, others think it’s crazy,” Dr. Gillespie summarized.
People have cited many different conditions that can be treated via medical marijuana—HIV/AIDS, neuropathic pain, epilepsy, multiple sclerosis pain. “I don’t know what people feel, and I don’t have a dog in the race,” said Dr. Gillespie. “I just try to stay objective.”
As such, he explained that the THC and Cannabidiol (CBD) present in the drug offer the potential to offer an individual benefits. “These days, insurance companies are getting involved and isolating the components,” he continued. “So if CBD has the most pharmacological promise, but doesn’t cause psychoactive problems, that’s what they will pursue. To me, that seems logical.”
Ryan Vandrey, PhD in experimental psychology, is an associate professor at the Johns Hopkins School of Medicine. Dr. Vandrey has done cannabis research for 18 years on numerous studies, including therapeutic effects, withdrawal effects, and other areas. “My stake in all of this is as a scientist interested in behavioral pharmacology in cannabis,” he said. “I want to identify interesting, important questions and develop data to inform policy and healthcare decision making.”
As for pain management, Dr. Vandrey clarifies that he does not treat patients as a clinician. “My observations are based on published data, not on directly observing patients,” he explained.
The logical place to start when looking at data, he says, is last year’s National Academies Report on Medicinal Cannabis. “Treatment of pain was one of three conditions they listed for which there was acceptable research indicating benefits—or in other words, cannabis could help.”
But not all pain, he cautioned, is the same. When going deeper into research, you find that most studies indeed support cannabis as being effective in neuropathic, chronic pain. This means that post-operative or other types of pain will not be relieved as easily. Additionally, several published studies indicate pain relief is secondary to the relief of other symptoms, such as in multiple sclerosis.
“You see a reduction in spasticity, or with epilepsy, a lower number of seizures,” Dr. Vandrey explained, “and secondary to that, you can get pain relief.”
Dr. Vandrey cited the lack of research into long-term effects on pain management, saying this was important when relating back to opioids. “in the short term, opioids are very effective,” he said. “But in the long term, people develop tolerance to the analgesia, leading to an escalation in dosage. You become more sensitive to pain as a result of long-term use. That hasn’t been evaluated in regards to cannabis.”
What about the downsides? All the typical effects of marijuana—paranoia, anxiety, mood and behavior—are still present. Some believe marijuana impairs psychomotor performance.
As for the toxicology, and smoke itself, there’s not nearly as much available data as there is for tobacco. But a number of carcinogenic compounds have been identified in marijuana smoke. Effects on the cardiovascular system are minimal and should not be a factor in otherwise healthy adults. Some respiratory problems are present—perhaps not to the extent of tobacco, but “it’s certainly not helpful,” said Dr. Gillespie.
The momentum of the legalization effort—whether medicinally or recreationally—is strong enough that more research is sure to be forthcoming, allowing experts like Dr. Gillespie and Dr. Vandrey to investigate and develop even more extensive knowledge in the area. For now, the summary is that any benefits should be specifically evaluated rather than accepted as universal answers.
“I would not go out and broadly say cannabis is a good pain reliever,” Dr. Vandrey concluded. “I think it’s much more nuanced than that.”
“Plug in any condition and we can say the following: we do not have sufficient evidence for physicians and patients to make an informed decision about medical use of cannabis.”