EW YORK — When she started collecting brains, neuroscientist Yasmin Hurd’s peers wondered what she could possibly be thinking.

Studying animals made way more sense as a way to trace how chronic drug use changes the brain, they thought — after all, how was Hurd going to parse the long-term effects from the trauma of the overdoses that killed the brain donors?

She waved her colleagues off. She wanted to know what was happening in human brains, not in mice.


So she began filling up freezers with slices of brain tissue from hundreds of overdose victims, most of them killed by too much cocaine.

“We had a lot of freezers, sadly,” said Hurd, who now runs the Addiction Institute at the Mount Sinai School of Medicine. And then, early in the 2000s, she noticed a tidal shift: Suddenly, the overdoses were dominated by heroin.

She saw the opioid crisis coming. Ever since, she’s been trying to figure out how to intervene — could she modify or reverse the way addiction changed the brains being studied in her lab?

Hurd has homed in on cannabidiol, one of the two main compounds plucked from the marijuana plant. She thinks it might hold the potential to curb cravings for heroin and other opioids.

She’s running against the wind. Cannabidiol is classified as a Schedule I drug, meaning the U.S. government thinks it carries severe safety concerns, no medicinal benefits, and a high risk of abuse. Even as a growing number of states legalize marijuana, the hard-line federal stance has made it difficult to do clinical research involving cannabis in this country.

But Hurd is throwing all of her weight into studying whether it can combat addiction. And she’s trying to rally other scientists to do the same, by creating a consortium to conduct cannabidiol clinical trials across the globe.

“If this is something that could be potentially beneficial, and there’s an indication that it could be beneficial,” Hurd said in an interview, “why not put all hands on deck?”

Hurd has the reputation and academic standing to pull this off — last fall, she was named to the prestigious National Academy of Medicine, along with dozens of other top-tier researchers.

More than that, she has determination: On the front of her computer screen, she’s stuck up a yellow Post-it note that says, “GAIN CONTROL.” Only she’s crossed out “GAIN,” and replaced it with “TAKE.”

Dr. Yasmin Hurd - Mt. Sinai
A scientist in the Hurd laboratory observes cultured striatal neurons under the microscope. Biz Herman for STAT

Unraveling the biology of addiction

Hurd has always had what she calls a “pure fascination” with the brain. Her own bounces quickly from one thought to the next, sometimes leaving threads unfinished for the sake of starting a new one. One idea may spin off into a dozen new ones. During a recent interview, she jumped from why she finds outliers in science so intriguing to why she loves murder mysteries (Alfred Hitchcock is a personal favorite).

That mental multitasking is mirrored in her lab, where her team is working on a slew of projects, from how chronic drug use restructures the brain to how the brain’s circuits play a role in psychiatric disease.

“My research, unfortunately, reflects me,” she said.

Her mind is constantly hunting for new ideas in unlikely, often difficult places — like on the list of Schedule I drugs.

Past studies have shown that cannabidiol works on a number of brain circuits involved in addiction and drug-seeking behavior. That’s made it an exciting pharmacological target — but the data, by and large, have just been preliminary and unpersuasive. Hurd started looking for more concrete evidence on cannabidiol.

“If this is something that could be potentially beneficial, and there’s an indication that it could be beneficial, why not put all hands on deck?”

Yasmin Hurd

The compound is one of the two main cannabinoids found in the marijuana plant, the other being tetrahydrocannabinol, or THC. But unlike THC, cannabidiol doesn’t get people high. Scientists are studying whether the compound can treat conditions such as epilepsy and anxiety. Hurd is testing whether cannabidiol can cut down on cravings in patients who are addicted to opioids — and in turn, can prevent relapse.

In her research on animals, the compound has decreased cravings and anxiety without producing any psychoactive effects. But she’s not sure why, exactly, it’s working. So at the same time, she’s orchestrating studies to delve into the biology that underlies addiction.

Some quick background: The neurons in the brain talk to each other through neurotransmitters such as dopamine, serotonin, and endocannabinoids. Those chemical messengers ferry information between brain cells through a synapse, which is the intersection between two neurons. Drugs like heroin are like a car crash — they damage those synapses to the point that other cars can’t get through.

Hurd’s lab is studying the wreckage through research like the experiment that one of her postdoctoral researchers, Noel Warren, is working on. Warren hits rat neurons with a compound that mimics chronic heroin use to see how synaptic plasticity — the way the brain changes the connections among neurons, forming new ones while pruning others — is different in the brain after drug use.

Based on her findings, Hurd has launched trials to test cannabidiol in humans — but that’s no easy task.

Dr. Yasmin Hurd - Mt. Sinai
Noel Warren, a postdoctoral fellow in the Hurd laboratory, which studies how drug use over time reorganizes the brain. Biz Herman for STAT

‘The hurdles are enormous’

Studying cannabidiol is daunting, and not just because the brain is so complex. To use cannabidiol or any part of the cannabis plant for research, a scientist has to get a special license from the Drug Enforcement Administration, which can take years. Then, scientists have to get approval from the Food and Drug Administration to administer it to patients.

“The hurdles are enormous,” said Margaret Haney, a neurobiologist at Columbia University who studies cannabis use disorder and the therapeutic potential of cannabinoids in humans. Haney has to keep the cannabis used in her trials in a gun safe that’s stashed inside a freezer that’s sitting in a special room in her lab that can only be accessed with her fingerprint. That’s routine for cannabis research.

And patients who are enrolled in clinical trials involving cannabis have to come to the lab of the researcher who holds a DEA license to get the drug, which isn’t always doable for individuals with serious medical conditions.

“Our hands are tied even though cannabidiol is not addictive,” Hurd said. But because it derives from the cannabis plant, the government classifies it as a Schedule I drug — like heroin, LSD, ecstasy, and peyote — which are considered to be harmful and have no medicinal value.


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That means there are relatively few scientists doing research involving cannabis, and even fewer studying its potential to treat addiction or testing cannabidiol in humans. Hurd isn’t in a crowded field.

“There’s really not that many people that do that,” said Dr. Sachin Patel, of Vanderbilt University, who has done research with cannabis to understand how marijuana exposure early in life raises the risk of psychiatric disorders.

And then, there’s the issue of supply.

For decades, the only sanctioned source of marijuana available for U.S. research was the University of Mississippi, which held an exclusive contract with the federal government.

“If you’re trying to do a clinical trial and you need cannabidiol, it’s actually quite difficult to get the types of cannabis needed to do the research,” said Patel.

Hurd said the restricted supply has made it all but impossible for her to study the specific formulations of cannabidiol she suspects would be the most therapeutic.

She is currently running Phase 2 clinical trials in New York to test cannabidiol’s ability to reduce cravings in people addicted to heroin. And she’s initiating similar studies to test cannabidiol soon in Canada and Jamaica.

But for Hurd, the process has felt painstakingly slow when people are dying so quickly. An estimated 63,600 people died of drug overdoses in 2016. Two-thirds of those deaths were caused by opioids.

Hurd is frustrated by how both the government is grappling with the crisis. It’s paled in comparison to the response to the Zika virus and other public health concerns in recent years, she said.

“People swarmed to do something. That did not happen with the opioid epidemic,” Hurd said.

Why not? Hurd blames it, in large part, on discrimination against people who are addicted to drugs. But if there were more federal funding for research, Hurd said, scientists could accelerate the search for solutions.

“You have to treat every epidemic the same,” she said, “whether it’s a drug epidemic or a viral epidemic.”

She’s quick to note that she’s not arguing that cannabidiol is a cure-all for the crisis. Hurd just wants to have enough researchers working on the problem that they can quickly say whether something works — or whether it doesn’t — and then move on.

Haney, the Columbia neurobiologist, echoed that frustration. The DEA said it has not rescheduled cannabis because there aren’t enough studies to show it has medical potential. But until it’s rescheduled, Haney said, those kind of large, randomized studies won’t really be feasible.

“We’re in a vicious cycle,” she said.

And dispensaries and cannabis companies in the 29 states that have already legalized medical marijuana don’t have any incentive to fund or conduct clinical trials on the medical benefits, experts say, because they’re already able to sell their products to patients without government approval.

“The money-making is all happening outside of any data,” Haney said.

So Hurd is trying to spur her fellow scientists to do as much research as possible on the potential of cannabidiol to treat opioid addiction, in a bid to build a cannabinoid consortium. She’s connected with clinicians, pharmacologists, and neuroscientists to talk about how to spur new research. And she’s working to rope in companies interested in cannabidiol, too. Without National Institutes of Health funding for such a project, she’s hopeful they’ll help fund the consortium.

Her goal: build an infrastructure that’s far broader than her own.

“I don’t need to be the only person in the room studying cannabidiol for opioid addiction,” she said. “It can’t be done with just one little Yasmin Hurd lab.”

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  • Cathy
    Sorry I have to answer at the top the software doesn’t allow more than one reply to a comment
    You asked if I know about paraganglioma tumors? Do you mean like the ones I have?
    There are other cancers besides your syndrome that produces NET tumors and I have 4 DIFFERENT tumors all from a different group than your
    I have mine in the pancreas the liver the intestines and the kidneys (both)
    I to have had MANY of surgeries to quell the symptoms and to reduce the size but at my stage, there is no real treatment or cure. We call it debulking to reduce the tumor burden so it can’t produce as much neuroendocrine componentry
    I have been using CBD for a LONG time without any THC and it has reduced my opioid intake to all but nill
    Without the CBD I would need quite a bit of narcotics to keep the pain limited so the CBD has worked famously, which is why we also recommend it to most of our cancer patients who are in either pain or nausea from the chemo we provide
    SURELY the CBD is no panacea like so many would like to proclaim and the more they widen the potential claims the less the FDA and the Gov will consider backing away
    If CBD was say ONLY valid for seizures then we could have had it approved decades ago and then everyone else could be using it “off-label” but instead we have so many websites and proponents claiming it is a cure for everything under the sun from psoriasis to cancer from HIV/AIDs to gum disease to infertility
    Pathetic instead of focusing and getting things moving they insist on trying to say how wide it’s scope which drives more and more scientific folks away
    We in science KNOW that if there was any panacea it would have been discovered by now and no one would die from disease only trauma or the like
    So sorry about your cancer BTW my suggestion is to go to the US TOP NET physician he is in Denver and his name is Dr. Eric Liu he is the nations most in-depth source of NET info and treatment and he is a good guy to boot (feel free to use my name to get an appointment)
    Dr. Dave

  • I’ve another comment on cannabis as medicine. There are phase trials being done at NIH by a British Pharma, GW Pharma, getting great results for epilepsy and there was a pain study. It is made from the plant and is not a synthetic. I also know a researcher in Israel studying its use in treating cancer, Dr. Meiri, and have had email communication with him hoping he could test my cancer but he’d need a mouse model and no mouse model exists for SDH Deficient Gist or Para. I’ve another researcher working with cannabis in Mexico City trying to help with me find a solution (there is no current cure for my cancer). My grower in Oregon was able to reduce her ovarian cancer tumor from 13 cm to gone with the use of cannabis. She can also make me any combination of THC:CBD that might work in my broken digestive system (I’ve a Kreb’s Cycle, Complex II DNA mutation, my father died of the same cancer). Before I ventured into cannabis I did research that showed in 2003 a patent was passed by our Senate that said cannabis had benefits. One name on that patent was Dr. Axelrod who was a Nobel Prize winning scientist. I then emailed the other two researchers and one still at NIH was only allowed to study the negative qualities. The other researcher in Alabama said he felt there was much potential but was no longer researching. GW Pharma has released and is about to release medications based on their NIH Phase Trials unfortunately I fear their price tag for a child with epilepsy is going to be $35,000 a year when those of us in medical states would pay 10% of that price from our dispensaries. With this current administration my husband and I feel there is no point in trying to change the minds of those in charge but we are sure that once the cigarette industry wants to get involved the laws will change fast as greed seems to be on the uprise these days.

    • The GW product is JUST a purified version of Charlotte’s Web extract
      They have decided to TRY to get IP for a plant substance and won’t get the approval here in the US. The Technion in Israel is the WORLD’s repository of all things MJ and CBD based. They have been researching THC CBD and the like since the 1970’s
      As far as treating and or curing cancer there is ABSOLUTELY no evidence that ANY compound in MJ or hemp has ANY ability to cure or treat cancer. With that said, however, there are LOTS of symptoms of cancer that can be minimized by the addition of CBD. A MUCH bigger potential is actually the turpines that are grown in the plants in smaller quantities and together with CBD have some promising potential
      There is NO need to pay for a pharmaceutical when you can get concentrated CBD without the affected THC from US-based oil companies who don’t require FDA approval
      We in the US need to stop asking for FDA approval and just ask to get the DEA out of the loop because this is ONLY a plant and like daisies and roses should be unregulated BUT not FDA directed
      Dr Dave

  • The DEA has made it harder to even get a drug license for class 1 in the last 10 years! Since 1996 when medical marijuana was legalized in California, the brakes have been on by the FDA and with Session at the DOJ, further government lethargy is present!

    • I am a bit older then you I am guessing but way back when we could all get Schedule 1 licenses just for the asking than in the late 80’s they charged OUTRAGEOUS biannual fees for the Sc1 so we all dropped them in favor of the Sc2 and 3 and the like
      I see NO reason for a clinical physician to have an SC1 license unless he/she is in research on a university level
      I have been researching CBD use for a decade almost and NO license needed beyond the typical medical one and typical liability insurance since CBD is legal in ALL 50 states as long as it comes from hemp and not MJ
      The DOJ is limited by the Congress and there is ABSOLUTELY no interest by the current Congress to change the law on MJ and THC
      I am one of three medical advisers to the US Senate and trust me it has been broached on numerous occasions and there is not enough political traction to even CONSIDER a federal bill to move MJ out of the DEA as it needs to be
      If it moves it will be removed not downgraded OUT altogether.
      Eventually, when all 50 states legalize MJ the fed will simply deregulate it and leave it as a plant for states to regulate on their own
      Dr. Dave

  • Two thoughts. I am a Stage IV cancer patient in a state where medical marijuana is legal (and now so is rec) . .. I’ve been following the science for five years. Up until recently cannabis was only allowed to be studied at the NIH for its negative qualities and I feel a lot of misconceptions came out of those studies. I’ve watch two fellow humans on cannabis who were there because of opiod addiction. The first cannabis wasn’t the “high” he wanted or needed. The second said “I got off my addiction to opiods in a week with cannabis” . .. So conflicting statements. I’m not on opiods for my Stage IV cancer but I do have a Vape Pen and use it nightly to help with sleep.
    Do I think it can kill pain as well as many of the pain medications . .. NO . . . Do I think it can help some with simpler symptoms YES. Do I think anyone medical patient should go to jail for trying this verses oxycodene NO! Thus we need to be open minded and help those we can with what they need. I DO NOT feel addicted to cannabis. If they took my supply (lots of organically homegrown in my closet) away tommorow I’d be fine (I think or I might have to ask for a pain med or a sleep med things allowed and sometimes expensive but insurance will pay for it.

  • Not sure the issue here. Since the 1938 law and SCOTUS ruling, the sister plant called Hemp which contains CBD but no THC has been legal in ALL 50 states
    We have been using CBD derived from hemp for about a decade now with chronic pain in cancer patients as well as nausea with chemotherapy with the same patients
    The patients can buy it have it shipped directly to them and it needs NO special license or authorization. NO, it won’t get you high or for that matter make you feel anything but a TERRIBLE taste in your mouth (really tastes bad) but the results are excellent
    I DO understand that the use of MJ is dramatically limited on a Federal level and in fact, I was the Director of the Federal Drug Interdiction Task Force many many moons ago before getting into surgery
    There needs to be a shift from J to hemp (two different plant species) so that we can THEN take the results from hemp and extrapolate it to MJ which has far more valuable terpenes that seem to be co-beneficial as well
    Synthetic CBD is all but a waste of time and surely money have tried it and the results cower in comparison yet PharmaCos still look to develop synthetics for patent protection capability that plants don’t provide
    Dr. Dave (head and neck cancer surgery)

    • Dr. Dave, I’m intrigued with your knowledge. You said “Head and Neck Surgery” are you familiar with carotid body tumors? That is one of the tumors my gene mutation SDHB can result in (a paraganglioma which my father died of). I’ve tried various forms of cannabis from tinctures to a gram a day of a 50:50 concentrate and as you said it did not help my control my tumor growth but it was very beneficial for sleep especially after a surgery that took 2/3rds of my liver due to mets. My grower/caretaker flew to Israel for their cannabis conference and she makes mainly CBD based products (she grew 600 CBD plants last summer and 12 THC with 6 that “had my name on them” as part of the Medical Marijuana law. There are only 200 cancer patients with my exact cancer and one is a cannabis grower who while in surgery had all his plants confiscated while he was in hospital to remove a 13 cm GIST tumor. As a rare cancer patient I’ve a FB Support Group and webpage where we freely discuss anything that can help us through a Stage IV diagnosis and I do agree with you and say “cannabis won’t cure your cancer” but it will help with symptoms.

    • Dr. Dave, Of course I know Dr. Eric Liu. My father died of NET tumors. I’d like to further discuss this. Are you willing to email me or look at my website or support site for NET and gist cancers? http://www.SDHcancer.org FB SDH Cancer Support – Gist, Para/Pheo . . . Or I’m a ‘friend’ on Dr. Lui’s FB page look and message Cathy Fr. . .

    • My husband died after four years of head and neck cancer 13 years ago. Until the end before he died pain was not so bad. Nothing worked then. I have Ms and bad pain. I had fentenyl patches finally at 100mc, but didn’t totally work. Then I went on methodone which worked for pain, but so. Hard to take. I got off. My girls have grown, so I started marajuana a few years ago. It really works great. No side effects except runny nose. I do need some thc ,thoughThat I don’t always like. It’s hard for me to see why it’s schedule 1 drug.

  • There’s an article daily about doctors claiming cannabis could be a piece to the opiod epidemic. Well I can tell you this without the PHd. Cannabis is the answer to opioids, and many other dangerous prescription pharmaceuticals. Doctors are so far behind the average cannabis user in their knowledge of the plant and how it can help medicinally. You’ll get far better information interviewing people from a local dispensary, than big Pharma bought doctors.

  • She should come to California. You can buy CBD products over the counter here. If you want marijuana, you have to go to a dispensary, but CBD is available in head shops, as is kratom.

  • I really wish someone like Sir Richard Branson could help with finance for these type of very worth while projects.wouldn’t it be great too be able to save all of the thousands of life how have been affected by opioid crises Good luck Yasmin Hurd hope you win

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