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?

If marijuana were going to bring down society, it probably would have already. Humans started using hemp from pot plants to weave clothes during the Stone Age, while later generations adapted the strong and flexible fibers to make sails and rigging. The Chinese began ingesting it around 2,700 BC, and it quickly spread from there. It’s included in the world’s oldest pharmacopoeia—a reference book for medicines and their uses—from the first or second century, and in later editions is mentioned as a treatment for a variety of ailments, including diarrhea and rheumatism.

Marijuana’s popularity as a medicine comes from its painkilling powers, but the drug doesn’t work like opiates such as morphine or oxycodone, which block pain signals but are highly addictive and can repress the respiratory system. Pot’s 80 cannabinoids, a type of chemical compound, stimulate the parts of the brain that influence pleasure, motion control, and memory, which can offer relief to people suffering from severe pain and muscle spasticity, and can help prevent nausea, which makes it useful to chemotherapy patients.

Marijuana, of course, can also be fun. The mind-altering use of pot in America started near the end of the 19th century, at Asian opium dens on the West Coast. In 1911, as Prohibitionist sentiment was peaking, Massachusetts became the first state to outlaw the possession of opiates and cannabis, or even merely being in the same room as the stuff. In 1937 Congress passed the Marihuana Tax Act over the objection of the American Medical Association, which made it illegal for anyone, including doctors, to move cannabis without proper documentation. Out of fear that it could destabilize the social order, pot was criminalized.

In 1970 the Nixon administration rewrote the drug code, reclassifying drugs based on their potential to harm or to help. Judges and federal drug agents decided, against the wishes of a few physicians who testified, to classify marijuana as a “Schedule I” drug, placing it alongside heroin and LSD. An age-old medicine was suddenly categorized as having no medical benefits and a high potential for abuse.

Yet the change did not deter the steady climb in usage rates. In 1969 Gallup polling found that 4 percent of American adults had tried pot. Four years later, that had tripled to 12 percent, and it doubled again to 24 percent by 1977. For teenagers, pot use among 12th graders peaked in 1978, when half of those surveyed admitted to smoking grass in the past year. Usage began a fairly steady decline from there, dipping to its lowest point in 1992, but the percentage of high school seniors who have tried pot continues to hover between 30 and 40 percent. Today, about half of Americans between 18 and 60 have tried marijuana at one point or another.