Lost in the Weeds

According to the polls, Massachusetts voters are going to overwhelmingly approve a ballot initiative next month that legalizes medical marijuana. That should be good news for someone like me, who’s spent half his life smoking pot. So why am I feeling so uneasy?

Just because pot remains popular, though, doesn’t mean it’s necessarily helping anyone. To learn more about its medical uses for the sick and suffering, I head to the Wellesley home of Lester Grinspoon, an associate professor emeritus of psychiatry at Harvard Medical School.

In 1967, Grinspoon was watching as his friends and contemporaries quickly adopted marijuana as their drug of choice. He feared that it “was a dangerous drug, no question about it.” Since he was an M.D., he took it upon himself to find definitive proof of marijuana’s harmful effects, then use what he’d discovered to convince young people to quit. Thus began an exhaustive review of the cannabis-related literature in the Harvard Medical School library. The more he looked, though, the more he became convinced that marijuana wasn’t dangerous. He published his results in Scientific American in December 1969, and two years later expanded his argument in a book called Marihuana Reconsidered. “At first I thought it was a terrible drug,” Grinspoon says. “But that first book was to reassure me and the rest of the world that we were all wrong about this, that this is a remarkably nontoxic drug. It’s the only drug I know of that you can’t…establish a death from it, from an overdose.”

Around the same time, Grinspoon’s young son, Danny, was diagnosed with acute lymphocytic leukemia. Grinspoon wouldn’t condone medical marijuana for his son, but his wife, Betsy, went behind his back and bought a little cannabis in the parking lot at Wellesley High School. She shared some with Danny before one of his chemo sessions. Gone was the anxious kid who vomited for hours after treatments. Instead, Danny asked for a sandwich on the ride home. “You have no idea what a relief it was for him,” Grinspoon tells me. “Not just for Danny, but all of us who saw the way he suffered.”

Danny passed away in 1973, but Grinspoon by then was personally and professionally invested in marijuana. He tried smoking it himself for the first time that same year, when he was 44. With President Nixon recently classifying it as a Schedule I drug, Grinspoon wanted to prove pot’s medical potential. He spoke with Emil Frei at Harvard Medical School about conducting a proper study on marijuana’s antiemetic effect—meaning its ability to curb nausea. Frei’s results, published in The New England Journal of Medicine in 1975, became the first American study proving pot’s effectiveness in reducing nausea. Grinspoon added to his own research with 1997’s Marihuana: The Forbidden Medicine, presenting hundreds of case studies that showed marijuana’s ability to ease the suffering of patients afflicted with conditions like multiple sclerosis, Crohn’s disease, cancer, AIDS, epilepsy, migraines, glaucoma, and arthritis. While there are synthetic marijuana tablets available by prescription, Grinspoon maintains that they don’t offer the full benefit of the whole marijuana flower.

Sit with Grinspoon long enough and you’ll believe what he does about the medical use of cannabis, that it “will be like penicillin seemed in the early ’40s—the wonder drug of our time.” I ask him whether he thinks the nature of his work affected the trajectory of his career. He suspects that he was never granted a full professorship at Harvard because of his research on marijuana, but says, “I am content that, ultimately, I have done more to relieve suffering than most of my colleagues.”

I leave Grinspoon’s basement office thinking that marijuana is clearly a valid medicine to help people who are suffering. But that doesn’t prove it’s not harmful to those who aren’t sick. Could weed be both beneficial to the ill and damaging to the future success of a guy like me? To find out, I call up Harrison Pope, a professor in the Harvard Medical School psychiatry department.

Pope, the director of McLean Hospital’s Biological Psychiatry Laboratory, conducted a number of marijuana studies between the late 1980s and 2000. I ask him if marijuana is dangerous over the long term. No, he tells me, but there are definitely short-term effects. “We had found from neuropsychological testing that chronic marijuana users exhibited difficulties, especially with verbal memory, for at least a week or two after they stopped smoking,” he says. So, the age-old stereotype that stoners have bad short-term memories is true. But thankfully, it doesn’t last. Pope tells me that in his studies, the memory problems disappeared within 28 days, and the adult pot smokers “were no longer distinguishable from the comparison group.”