Posted on

marijuana study harvard

Many patients find themselves in the situation of wanting to learn more about medical marijuana, but feel embarrassed to bring this up with their doctor. This is in part because the medical community has been, as a whole, overly dismissive of this issue. Doctors are now playing catch-up and trying to keep ahead of their patients’ knowledge on this issue. Other patients are already using medical marijuana, but don’t know how to tell their doctors about this for fear of being chided or criticized.

Least controversial is the extract from the hemp plant known as CBD (which stands for cannabidiol) because this component of marijuana has little, if any, intoxicating properties. Marijuana itself has more than 100 active components. THC (which stands for tetrahydrocannabinol) is the chemical that causes the “high” that goes along with marijuana consumption. CBD-dominant strains have little or no THC, so patients report very little if any alteration in consciousness.

The most common use for medical marijuana in the United States is for pain control. While marijuana isn’t strong enough for severe pain (for example, post-surgical pain or a broken bone), it is quite effective for the chronic pain that plagues millions of Americans, especially as they age. Part of its allure is that it is clearly safer than opiates (it is impossible to overdose on and far less addictive) and it can take the place of NSAIDs such as Advil or Aleve, if people can’t take them due to problems with their kidneys or ulcers or GERD.

Uses of medical marijuana

Along these lines, marijuana is said to be a fantastic muscle relaxant, and people swear by its ability to lessen tremors in Parkinson’s disease. I have also heard of its use quite successfully for fibromyalgia, endometriosis, interstitial cystitis, and most other conditions where the final common pathway is chronic pain.

There are few subjects that can stir up stronger emotions among doctors, scientists, researchers, policy makers, and the public than medical marijuana. Is it safe? Should it be legal? Decriminalized? Has its effectiveness been proven? What conditions is it useful for? Is it addictive? How do we keep it out of the hands of teenagers? Is it really the “wonder drug” that people claim it is? Is medical marijuana just a ploy to legalize marijuana in general?

This is not intended to be an inclusive list, but rather to give a brief survey of the types of conditions for which medical marijuana can provide relief. As with all remedies, claims of effectiveness should be critically evaluated and treated with caution.

Patients do, however, report many benefits of CBD, from relieving insomnia, anxiety, spasticity, and pain to treating potentially life-threatening conditions such as epilepsy. One particular form of childhood epilepsy called Dravet syndrome is almost impossible to control but responds dramatically to a CBD-dominant strain of marijuana called Charlotte’s Web. The videos of this are dramatic.

The MIND program is also conducting medical cannabis research studies involving veterans, women with menstural- and menopause-related problems, and chronic pain sufferers. In addition, Gruber’s lab has launched the nation’s first clinical trial to compare the effectiveness of two different formulations that include cannabidiol (CBD)—a non-intoxicating component of cannabis—for treating anxiety. Patients will receive either a full-spectrum product that is high in CBD and contains other cannabinoids and terpenoids (organic compounds that provide aroma, flavor, and may also have their own effects on the body); a single-extracted compound form of CBD from the same source; or a placebo. Gruber wants to know whether the full-spectrum version will work better to reduce anxiety, which affects millions of Americans. This project has received a small grant from the larger $4.5 million gift to HMS from Harvard alumnus Charles R. “Bob” Broderick, AM ’05, to fuel cannabis-related discovery.

Gruber, a Harvard Medical School associate professor of psychiatry, directs both the Cognitive and Clinical Neuroimaging Core and the Marijuana Investigations for Neuroscientific Discovery (MIND) program at McLean Hospital. She and her team are using cognitive and clinical measures, as well as neuroimaging techniques like functional MRI, to help elucidate how cannabis affects the human brain. They have discovered, for example, that individuals who start heavy recreational marijuana use before age 16—when the brain is still developing—may perform more poorly on cognitive or behavioral tasks involving the frontal cortex, such as memory, attention, and judgment, than those who don’t use cannabis or who started using it later in life. A recent paper that Gruber co-authored underscored these findings using results from a simulated driving test. Neuroimaging has also revealed changes in white matter, the neural fibers critical for efficient communication among brain regions, in early-onset cannabis users.

Gruber is especially excited about her team’s research on medical cannabis and its effect on cognition, brain structure, function, and quality of life. “Almost no literature exists on the long-term impact of medical cannabis,” says Gruber, who launched the MIND Program in late 2014 to address that gap. “So many people are desperate to find anything that works to alleviate their symptoms. It would be fantastic to know what actually does and does not work for patients over time.”

MIND Matters

Encouraging results have emerged from MIND’s first investigation, a longitudinal observational study of individuals using medical cannabis for various conditions and symptoms. The team conducts multiple assessments before participants—who choose their own products—start treatment. Further testing happens at three, six, 12, 15, 18, and 24 months after their treatment begins. Even after a few months, patients performed better on cognitive tasks requiring executive function; “Rather than getting worse, they’re actually getting better,” Gruber says. This contrasts with poorer cognitive performance seen among some heavy recreational marijuana users relative to non-users. Patients in this pioneering study have also reported improved mood, energy, and sleep, and reduced use of conventional medications.

Cannabis products are everywhere these days. As a growing number of states loosen their medical and recreational cannabis laws, millions of Americans are using the cannabis sativa plant, typically known as marijuana, to relax or treat pain, anxiety, insomnia, and other conditions. Yet more data is needed on its impact. “The nation has warmed toward the use of cannabis, but policy continues to outpace the science,” says neuroscientist Staci Gruber, EdM ’95, PhD, who’s working to change that.

What explains these improvements? Gruber says patients may be thinking more clearly because their symptoms are alleviated, and/or because they are using less conventional medication such as opioids. In addition, medical cannabis patients tend to be older than recreational users, and she says there’s some preclinical data suggesting that cannabis may help boost the body’s aging endocannabinoid system—a natural system that helps regulate key functions such as sleep, mood, appetite, and memory.

Gruber’s 20-plus-year quest to understand how cannabis affects the brain began with a life-altering college summer internship at McLean, located in Belmont, Massachusetts. “I fell in love with clinical trials and neuropsych assessment and testing and thought, ‘I can’t imagine doing anything more exciting than this,’” she recalls. She remained at McLean and collaborated with McLean researchers throughout her college, graduate, and post-graduate years and then joined the faculty. Gruber says she is honored and humbled to work with the dedicated patient volunteers in her studies. “And if we’re doing something that helps improve the quality of life for any patient group, we’ve changed the world.”

HILL: I think the greatest example is when you talk about the addictive nature of cannabis. You can become addicted to cannabis, though most people don’t. Yet invariably, when people hear about what I do, they say, “Oh, you’re an addiction psychiatrist? Well, cannabis is not physically addictive; it’s psychological.” So there are fallacies about cannabis. And they continue because people are invested in trying to get people to vote one way or another on issues like medical cannabis or legalization of recreational cannabis. That is a major problem. Every single day we have patients come in who are interested in using cannabis as a medication or they’re using it recreationally or are interested in cannabidiol, and they have beliefs about cannabis that they’ve held for years that aren’t true. And that becomes a major barrier. It’s hard to dispel those beliefs in the office.

HILL: How are things misrepresented by anti-cannabis crusaders? They tend to ignore the idea that dose matters. When we talk about the harms of cannabis, young people using regularly can have cognitive problems, up to an eight-point loss of IQ over time. It can worsen depression. It can worsen anxiety. But all of those consequences depend upon the dose. The data that shows those impacts look at young people who are using pretty much every day. They’re heavy users who usually meet criteria for cannabis-use disorder. So when people who are opposed to cannabis talk about those harms, they don’t mention that they’re talking about heavy users. The 16-year-old kid who uses once or twice a week, I’d still be worried about it, but that use has not been correlated to these harms.

Is delta unstoppable?

"There are a lot of things we don’t know, and a lot of answers we wouldn’t have expected" says Kevin Hill, who has conducted marijuana-related research and is the author of “Marijuana: The Unbiased Truth about the World’s Most Popular Weed.”

GAZETTE: Marijuana legalization has swept the country over the last couple of years. What do we know now about its health effects that we didn’t know before?

HILL: We’re conditioned as physicians to believe that cannabis is bad for you, but there is data that it can be useful in certain cases. I would prefer that we use FDA-approved medications when possible. They are much safer, and you can be sure of the purity and potency. But there is evidence to support the use of cannabis and cannabinoids for a handful of medical conditions. That is dwarfed by the number of conditions for which people are actually using it, but the evidence of benefit is not zero. To a lot of doctors, it’d be convenient if it was zero so they could tell patients that this whole idea is a sham. Thus, there are physicians who aren’t willing to entertain data demonstrating therapeutic use of cannabis. I think that’s a missed opportunity because if a patient comes in and says, “I want to use cannabis to treat condition x,” cannabis might not be the best treatment for that condition, but just being willing to engage in a conversation about it, you may get them into treatment they might not otherwise get into. If they said, “Look, I want to use cannabis to treat my anxiety,” I’m not going to recommend using whole-plant cannabis to treat anxiety, but maybe they haven’t tried cognitive behavioral therapy. Just by having that conversation, you could do a lot of good.