The Curious Case of Cannabis

Igor Grant, MD, chair of the Department of Psychiatry at UC San Diego School of Medicine

With California’s recent legalization of recreational-use marijuana, interest and debate has never burned hotter at UC San Diego’s Center for Medicinal Cannabis Research (CMCR). Established by the California State Legislature in 2000, CMCR was the very first cannabis research facility in the United States, currently headed by Igor Grant, MD, chair of the Department of Psychiatry at UC San Diego School of Medicine. We asked Dr. Grant about the early days of cannabis research, where the field is now and what lies ahead.

Why should we study cannabis?
Over the years there has been a lot of anecdotal evidence that cannabis is medically helpful, but there have been precious few academic studies that verified this. When the Center for Medicinal Cannabis Research was set up, we were one of the first groups to look at this question seriously and conduct controlled studies. There had been a lot of “buzz” out there, but not many facts to support it.

What piqued your interest in the substance?
As a medical student trainee at the University of Pennsylvania, I became very curious about the possible negative effects on cannabis use on the brain. There was a lot of conversation at this time—especially since use was increasing during late 1960s and early ’70s—that pot would make you stupid or cause your brain to rot. So I and another trainee conducted a neuropsychological study of Penn medical students, some who were users of pot and others who were not. It turned out that there was absolutely no difference between users and non-users, so that piqued my interest in other drugs of abuse and their effects. A good part of my career has focused on alcohol and other drugs and their impact on the brain and behavior.

Why has use of cannabis become such a controversy?
My belief is that by mixing up social policy with the medical side, we have created a problem that didn’t need to exist. Cannabis consists of many chemicals—some of which may have therapeutic value and others that may not. Like all medicine, cannabis has pluses and minuses. There are no perfect medicines or medicines that are perfectly safe, and cannabis is no different.

Historically, cannabis was one of many botanical products thought to have medical value. At the end of the 19th century, cannabis was used as medicine for pain and other indications. I even have a picture of a bottle from the Eli Lilly Company circa 1913 that states on the label: Cannabis Americana. Analgesic. Hypnotic. Antispasmadic. With increased use, some of the abuse properties became more evident, which led to a backlash and more of a criminal justice approach resulting in a series of laws that criminalized this substance. But the question remained: Was cannabis was just something hippies and disreputable people partook in and thus should be illegal? Or was it something that could be of value medically?

What do you think is the biggest public misconception about cannabis?
I believe there are a couple, one at each end of the spectrum: That it is entirely safe and that it is terribly dangerous. On the one hand, proponents for legalization often assert that cannabis is perfectly safe, i.e.less toxic than alcohol. It is probably true that cannabis is less toxic than alcohol, but is not true that it is perfectly safe. At the other end of the spectrum, there are people who say cannabis is the devil’s work or that it is a gateway drug, rots your brain and causes cancer. These claims are not true.

We know that cannabis can affect your perception, make you drowsy and impact your reaction time—all factors that could impact driving if you are stoned. We also know that cannabis and TCH impact memory, at least while you are stoned. So if you’re trying to study while high, chances are you won’t remember what you were trying to learn. The long-term effects of moderate cannabis use are subject to some debate. My own interpretation of the existing data is that there are few clearly documented long-term health effects.

How do you see cannabis legalization playing out in coming years?

It’s a great social experiment. The so-called War on Drugs has been going on for more than 40 years with an estimated trillion dollars spent, but if you look at usage patterns for marijuana, they have largely remained the same despite all the time, money and effort to curtail its use. Hopefully legalization will move us away from the War and onto more positive and productive paths. Having said that, however, legalization could lead to a perception that marijuana is perfectly fine for everyone. But just like tobacco and alcohol, marijuana is not perfectly fine for everyone, and people should be wary.

What excites you most about the future of cannabis research?
As a physician, the most exciting thing for me is having new medicines that can help patients who haven’t found relief through existing remedies. Chronic pain is no fun and if whatever you are taking isn’t helping or the amount you must take creates toxicity, it’s exciting to think cannabis may offer an alternative. Another aspect is the role cannabis could play in dealing with the opioid crisis. In states where cannabis has been legalized, opioid-related deaths, overdoses and the number of prescriptions
have decreased. Although we don’t know yet if this is a cause-and- effect relationship, we have heard from patients that they are able to decrease or replace opioids with cannabis as a less toxic or addictive alternative.

What will be the role of CMCR?
CMCR has been at the forefront of showing that cannabis is of value as a medicine. We’ve seen several medical uses, especially for neuropathic pain (caused by damage or disease to the sensory nervous system, commonly associated with conditions like diabetes and HIV/AIDS) and muscle spasticity in multiple sclerosis. Moving forward in our research, we want to see if an active compound in cannabis may be helpful in treating specific autism symptoms. We would also like to study cannabis and the treatment of anorexia nervosa, post-traumatic stress disorder and early psychosis. Hopefully CMCR will play a role in making discoveries in these areas.