I remember one of the clients I had on internship. He’d been drinking a fifth of bourbon a day for years. As you’d guess, his liver was a mess, and his thinking was clearly impaired. I couldn’t help but wonder how much better his health would have been (and how much money he could have saved) if he’d used cannabis instead. Of course, if I’d suggested that he switch to a safer drug, my supervisor would have berated me so loudly that everyone in the clinic would have had to cover his ears. There was little evidence to support this practice, no matter how much I thought it might help.

Although the idea remains controversial, substituting cannabis for drugs that cause more harm has a ton of advantages. It can certainly be cheaper, easier on the body, and less impairing. Harvard professor Lester Grinspoon mentioned this idea decades ago. I must get two e-mails a week from people who swear by the practice, but individual cases hardly count as compelling evidence. Fortunately, real people with real problems do everything that they can to tackle their troubles, no matter what the published research might say.

Years after I left internship, Dr. Amanda Reiman showed that many patrons of the Berkeley Patients’ Group used the plant to decrease or stop their consumption of other substances. The obvious next step would be a randomized clinical trial. Folks with drug problems would be randomly assigned to receive treatment as usual or to use cannabis exclusively instead. We’d follow up with them later and see how they were doing. Then we’d know if the treatment was helpful. It would take some money to give them the treatment they needed, but no matter how the experiment turned out, we’d know something very valuable.

If I’d called the National Institute of Health to pitch this idea, they’d probably have laughed their heads off. They’d have said that everybody knows that you can’t treat alcoholism with cannabis. I’d have mentioned Dr. Reiman’s study. They would have said that it was just one sample, and they were all from the same place, so no dice.

For this reason, we wanted to know if more medical cannabis patients made comparable claims. My esteemed colleagues contacted over 400 medical cannabis patients who were patrons of four different dispensaries in British Columbia. (I was just the data monkey on this project. Once New York state becomes more enlightened about medical cannabis, I’ll be more help.) Over 75% of these folks said that they used cannabis in place of some other drug. Replacing prescription drugs was the most common practice (68%), but many used the plant instead of alcohol (41%) and illicit drugs (36%). (Participants could report more than one drug for substitution, so the totals don’t equal 100%.)

We now have literally hundreds of people reporting that they can use cannabis instead of drugs that cause more harm. People who use alcohol or other drugs problematically often balk at treatments that demand complete abstinence. Who might show up for treatment if patients knew that they could use cannabis as part of the program? Maybe they’d run into trouble with the plant. But maybe they’d have healthy, productive, fun lives. They’d certainly have fewer problems if they laid off stimulants, alcohol, or opiates. So, how about it? What will it take to get a harm reduction program going where folks can use cannabis instead of hard drugs? I hate to think that the world might never know.