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BELMONT, Mass. — Staci Gruber vividly remembers her first hit of marijuana, back when she was in college. It made her so paranoid, she locked herself in a bathroom. She couldn’t decide whether to remain in hiding or to run. But she knew she’d never try pot again.

She didn’t lose interest in the drug, however. Today, she runs the 2-year-old Marijuana Investigations for Neuroscientific Discovery, or MIND, project at McLean Hospital in this suburb of Boston. With cognitive testing and neuroimaging, MIND is conducting a longitudinal study of medical marijuana.


“There’s a lot we don’t know about long-term effects, and that’s what I’m here to find out,” Gruber said.

Gruber, 49, has already made her mark on the field.

She ran a small study, published in 2013, that found teenagers and young adults who smoked marijuana were more likely to exhibit impulsive behavior than their peers and were more likely to have certain changes in the brain’s white matter. A followup study found that those changes could reorganize brain regions associated with inhibitions. This year, Gruber’s research team also found that chronic recreational users of pot had poorer cognitive and executive functioning, particularly if they began using marijuana as teens.


MIND’s current work involves adults who are legally permitted to use marijuana-based products for medical conditions. The researchers are particularly interested in the non-psychoactive components of the marijuana plant, such as cannabidiol, an ingredient in many preparations of medical marijuana.

“We have this one word, marijuana, which we think means every part of the plant, and it doesn’t. The cannabinoids I study aren’t even the ones that get you high,” Gruber said. “But whether you’re for medical marijuana or against it, what we really need is information.”

Marijuana has been studied before. But previous research has focused on the cognitive effects of smoking pot recreationally. Earlier studies of medical marijuana have looked mostly at efficacy — how well it treats symptoms of conditions like multiple sclerosis, cancer, and HIV/AIDS.

Gruber and her colleagues, by contrast, are trying to determine the long- and short-term impact of medical marijuana on cognition, brain structure and function, quality of life, sleep, and other clinical measures. 

“[This] is a primary concern for patients considering cannabinoid treatment, and it may have implications for public policy,” Gruber said.

Gruber lab
Gruber runs the Marijuana Investigations for Neuroscientific Discovery at McLean Hospital. Kayana Szymczak for STAT

Peering into the brain

The first phase of the MIND study is observational. Before patients begin their treatment, Gruber and her colleagues establish a baseline — using imaging, interviews, and task performance tests — to see what patients’ brains look like before they use medical marijuana.

The patients then record how much marijuana they’re using, and how often. At intervals of  three, nine, 12, 18 and 24 months, MIND researchers conduct more tests, brain scans, and interviews to measure the effects of the cannabis on their brain structures, cognition, and daily life. 

This is the part of Gruber’s research that will be most valuable, said Madeline Meier, a marijuana researcher at the University of Arizona.

“The most important goal right now is to obtain high-quality data on the potential harms and benefits of cannabis,” Meier said.

There are currently 30 study participants; Gruber plans to enroll up to 200. A separate MIND study will examine military veterans who use cannabinoids. 

“People drive two to three hours sometimes to get [here for] the study,” Gruber said. “They’re really committed. They really want to know what effect this will have on them.”

As they wait for long-term results, MIND researchers have made a few interim discoveries. They have found, for example, that marijuana could possibly ease symptoms for people with bipolar disorder and that a medication for strokes and Alzheimer’s disease may reverse the cognitive effects of chronic recreational marijuana use.

Gruber’s earlier findings, raising red flags about the dangers of recreational pot smoking, have caught the eye of some activists, like the Seattle-based drug prevention program SAMA, short for Science and Management of Addictions.

“We brought her out here because she had done this great research on adolescents and THC,” said SAMA president Kim Brackett. “We call her ‘the rock star scientist.’ She has a very nice way of translating scientific information in a way that non-scientists can understand, from grandparents to 8-year-olds.”

New interest in funding research

The patients in MIND’s studies bring their own marijuana products, which Gruber’s team analyzes for potency. Studying marijuana can be challenging because the federal Drug Enforcement Administration classifies it as a Schedule 1 drug, a category reserved for substances with a high potential for addiction and no medicinal value. The DEA recently considered changing that classification — but decided not to.

As a result, the federal government is currently the only approved source of cannabis for clinical trials of medicinal marijuana. “But that’s not what people are using,” said Francesca Filbey, who researches marijuana at the University of Texas at Dallas. “The only way science can study what people do is to let them do it.”

Gruber, Filbey, and several other researchers have formed a consortium, dubbed IDEAA, to pool their research data. Their goal is to make their data widely available, and to get more funding for marijuana research.

“We also hope to do some joint projects — pun intended — that can get funding,” Gruber said. “People are warming up to the idea of marijuana as medicine and funding is opening up.”

For now, Gruber’s project is funded with private donations. The first one came in 2014 when MIND launched with a $500,000 gift to McLean Hospital from Gruber’s wife, crime novelist Patricia Cornwell. The two married in 2006, having met when Cornwell visited McLean to research a book.

“She was asking a lot of really good questions,” said Gruber. “Then I found out she wanted to meet and talk more. We went out for dinner and ended up talking about neuroscience until 2 o’clock in the morning.”

Gruber first came to McLean Hospital in the 1990s to work as a lab assistant while completing two undergraduate degrees at schools 10 miles apart. She majored in psychology at Tufts University in suburban Boston. She was also studying vocal performance and jazz at the New England Conservatory of Music.

“I spent most of those years just running,” Gruber said, shaking her head with the memory. “You look back and wonder, ‘How did I ever do that? I could never do that now.’ I guess that’s what’s great about being young.”

While in college, Gruber landed an internship at McLean in a lab studying the effects of marijuana on college students. “From there,” she said, with a wait-for-it grin, “I was hooked.”

She continued working at McLean while earning graduate degrees in psychology and experimental cognitive neuroscience at Tufts and at Harvard, where she is now an associate professor.

‘It takes emotion and soul’

While Gruber has always loved music, she’s only recently fully embraced that side of herself.

“When I was little, I used to sing in the closet because I was terrified that I wasn’t any good,” she said. “But then I had this music teacher who said, ‘Hey you, you should have a solo.'”

At the conservatory, she fell in love with jazz singing, which she said resonated with her much more than classical arias.

“If you’re not feeling what you’re doing, what’s the point?” she said. “And that’s true in science, too. You can scientifically break down all these parts of music, like tone and pitch, but it takes emotion and a soul to make it real. In science, you can have all the findings in the world, but if you can’t communicate them, what good are they?”

Today, Gruber has a home studio and a Youtube channel for her music, which includes covers of popular songs along with her own compositions. And she has recorded two CDs.

But, she insisted, “I’m still the kid in the closet. I mean, I get media calls to talk about medical marijuana and I can do that, but singing? I’m a neuroscientist. Do I really want people hearing me sing a Sara Bareilles cover?

“It’s okay to not be comfortable 100 percent of the time,” Gruber added. “You have to put yourself out there, to sing and be true and be you.”

That is no more than what she asks of study subjects, she explained.

“The whole point of this is getting people to tell the truth, sometimes about illegal activity, so they have to trust you,” she said. “I don’t know that I would be able to do studies like this if I couldn’t connect with people.”

Editor’s Note: Comments have been disabled for this article.

  • Been smoking since 1967. Just ask me what you want to know and you have your answer for the majority of us. Cough up goobers every day and it get worse if you quit. Can’t smoke as much as I would like as it is too hard on my throat. Three joints a day is total max. Never smoke if I have any kind of business to do that day. Can go to Vegas and do without for a week. No big deal. Have driven stoned for 900 miles at a time many times. Never an accident. Smoke to forget. Does nothing for pain. Say legalize it and tax it. Can’t stop folks from using it.

  • This article is nothing more than Boston Herald caliber click bait. There are millions of highly intelligent and accomplished people throughout the world who smoke herb and use other drugs(myself included) who lead lives of unfathomable success and substance. The best part is that amongst the ones I associate with, none of them had to marry up to get there.

  • Cannabis is not monolithic: there are dozens if not hundreds of different strains grown by thousands (if not millions?) of different growers in different ways in different environments in different mediums using different nutrients, different growing, different trimming and different curing techniques – producing an infinite number of different combinations of the many cannabinoids, terpene, and flavonoids that mix together to form an infinite array of varying effects. So far researchers say they’ve found over 400 different combinations of unique therapeutic compounds.

    Even the same genetics grown by the same grower under the same conditions can have huge variations in outcome for any number of reasons. Just like not every grape is the same every year it’s grown for wine making.

    Testing the plant at different times during it’s growth produces different test results. Testing different parts of the plant produces different results. Buds at the top test differently than buds at the bottom of the plant.

    Catch my drift?

    How can anyone do a credible study – long or short term – on “cannabis”?

    Which “cannabis”? Grown by whom? Under what conditions? Indoor? Out door? With which genetics? What strain? Grown from seed or clone? Was it a “feminized” seed? Grown in what kind of medium under what kind of environmental conditions? With which cannabinoid, terpene and flavonoid profile? How much myrcene is in it? How much limonene? How much cannabigerol? How much CBN? What’s the THC/CBD ratio?……

    Cannabis research must be “strain specific” and/or “profile specific”.

    Researchers are starting to discover that specific cannabis strains are better for certain diseases.

    That should be the focus of research. Not this tired old “we just don’t know enough about the long term effects”. Hogwash.

    We’ve had an FDA approved/ DEA sanctioned 100% THC medicine available by prescription in all 50 states for over 30 years now since 1985 without any sordid stories of brain damage or any other adverse long term effects. Seen any articles? Not one. Anywhere. Ever.

    There are still four remaining patients from the Federal Gov’t.-run Compassionate Investigational New Drug Program started in the 1970’s who have been receiving 360 pre-rolled marijuana joints for over 30 years now without any adverse effects at all. As in none.

    Our own taxpayer dollars have been funding Israeli cannabis research for over 40 years now through grants from the NIH of $100,000. per year to the father of modern cannabis research and his associated research teams, Raphael Meschoulam.

    As a direct result of this research, in Israel cannabis is treated as medicine and is smoked, vaporized, ingested and injected in Israeli hospitals administered by licensed MD’s and medical professionals and is available by prescription at pharmacies in raw flower form, edibles, concentrates, oils and tinctures.

    The one long term IQ study from New Zealand from the 1970’s that claimed an 8 point IQ drop and profound cognitive decline in under age teens who started long term pot smoking before the age of 18 that everyone quotes as “proof” of how bad long term pot smoking is, interestingly also states quite clearly in the very same study in the very same paragraph that they found absolutely no IQ drop or cognitive decline of any kind at all in teens who started long term pot use after age 17. None. As in zero. Look it up.

  • I owned a small business and employed a young person as a tool maker trainee.
    He was very smart. When he first started his training he accomplished many
    things on his own. He started smoking marijuana when his mother had cancer.She was using it to relive the pain. After she died he continued to use it. In about 2 Years his mental ability deminished to a point where he could
    not do the work that he did on his own when he first started to work for me.
    He went from tool maker to just being able do less important tasks.

    This was about 1980-85
    He remained a nice person but eventally went on to coke.

    Im totally against the use of marijuana.

    • I find it interesting that you blame the marijuana for his change in behavior and not the rather extreme life changes which he went through during the period. The simple reality is that millions of people operate functionally and without significant cognitive impairment in this nation every day.

      The vast majority of people who consume cannabis don’t go on to become coke users, as well, which is a surefire tell that the problem in this case wasn’t the marijuana. The person in question very clearly was going through a much larger life issue.

      Robert, you simply have no idea what you’re talking about and you’re making poor assumptions about your anecdote. You need to come to terms with the fact that your conclusions are based on poor information.

  • For now, Gruber’s project is funded with private donations. The first one came in 2014 when MIND launched with a $500,000 gift to McLean Hospital from Gruber’s wife, crime novelist Patricia Cornwell. The two married in 2006, having met when Cornwell visited McLean to research a book. She’s living of her ring wing mommy wife. Get a clue. These minges are off the hinges.

  • What Staci did not probably know, that first hit of mary jane, could of had some LSD, or some thing baaaad, maybe a coworker trying to get into her pants.
    The story would of made more Cent’s $ if it started out with truth. Smoking POT will not do what she said. A lab monkey will die if made to smoke cig’s all day, a drunk that drinks every day for years will die. The life span is higher than ever, but no one factors, murder, cars, planes, trains, boats etc. accidents. Did she have to hold down the little guys to make them inhale ? The term study says long term: really ? She is not old enough to say any thing about long term. Her point is purely a guess. But she got her 5 minutes of media, which makes her happy.

  • She is going to find out for sure what damage is done. It is likely she will find that it cause some to every one and a lot to a few. Especially if smoked. You cannot make it clean. It will always have damaging qualities[cancer for one].

    • Dr. Donald Tashkin’s early research many years ago that found pot smoke contained carcinogens led everyone to believe severe lung diseases were inevitable from smoking marijuana and was given millions by NIDA to support his research and prove a causal link to lung cancer, COPD and emphysema.

      After 30 years of numerous, exhaustive and varied studies including the largest case controlled study of it’s kind tracking approx. 2500 patients for 30 years in conjunction with several other research teams from well known institutions like Harvard and the Albert Einstein College of Medicine spending millions from NIDA with a mandated bias to study only the negatives of drug use and pot smoking and not the medical benefits, he states unequivocally:

      “We’ve been unable to find any positive association at all with increased rates of lung cancer, emphysema or COPD in even the heaviest long term chronic smokers.” None. As in zero.

      In fact, their rates were lower than both the tobacco and non-smokers. They also had lower rates of head, neck and throat cancer.

      “We hypothesized that there would be a positive association between marijuana use and lung cancer, and that the association would be more positive with heavier use.”

      “What we found instead was no association at all, and even a suggestion of some protective effect.”

      He acknowledges this was “against expectations and counterintuitive” but none the less true.

      Dr. Donald Tashkin is Medical Director of the Pulmonary Function Lab at UCLA Medical Center and has spent his entire career researching the pulmonary effects of tobacco and cannabis. He and his associated research teams are responsible for the majority of the research in this field. He is the world’s leading authority on the subject.

      Anyone can easily access an online video interview with Dr. Tashkin himself and hear it directly from him and/or read the original source research documents of Dr. Tashkin, et al., and verify this information for themselves.

      Cannabis has been used for centuries all across the globe and in more recent history pot smoking has skyrocketed all over the world for well over the last 50 years with millions and millions of people smoking tons and tons of pot with abandon. It wasn’t just invented yesterday.

      If pot smoking caused severe lung ailments it would have shown up all over the world in every pulmonary specialist’s office and every respiratory therapist’s office and every oncology dept in every hospital around the world by now. The govt and every media outlet would be blasting headlines reporting this worldwide devastating epidemic. Where are the bodies? Where are all these lung diseased people? No where to be found. None of this is happening. Anywhere.

      There are still four remaining patients from the US Federal Govt-run Compassionate
      Investigational New Drug Program started in the 1970’s who have been receiving 360 pre-rolled marijuana cigarettes every month for over 30 years now from the only federally run pot farm at the U. of Mississippi without any adverse effects at all. None.

  • And drug dealers and junkies post their louse marijuana propaganda all over th einternet. marijuana shrinks your brain forever – 50% of users never regain their brain activity. e-cigarettes and other vapor crap – thats toxic aerosol that destroys your lungs?, blood cells, brain, sexuality and gives you leukemea and other forms of cancer. drug dealers must sit in prison and not roam around selling poison to teenagers.

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