From Thursday's commentary page, by George Ball:

We live in a time that merits a new edition of Extraordinary Popular Delusions and the Madness of Crowds, Charles Mackay's classic 1841 study of human follies and frenzies, including witch hunts, alchemy, and bursting financial bubbles. One delusion now in full bloom is the movement to legalize medical marijuana, which is proceeding apace without significant care or consideration on the part of the government, the medical and scientific community, or the public.
With California leading, 14 states have legalized medical marijuana, and 11 others are considering doing so. New Jersey's governor and lawmakers recently wrangled over implementation of its new medical-marijuana law, while Philadelphia's current and former district attorneys argued about a push to lessen penalties for possession.
This rampaging weed of a public policy seems eerily immune to the kind of scientific testing and review routinely accorded to the regulation of food and medicine. You might think marijuana — classified as a federal Schedule I drug, or one with a high potential for abuse and "no currently accepted medical use" — would get special scrutiny before it's approved as medicine. You would be wrong.
On this issue, the public and policymakers have thrown caution to the smoke-filled winds. California's medical-marijuana laws are a hodgepodge, changing from county to county like something dreamed up by Cheech and Chong. Today there are reportedly about 600 marijuana dispensaries in Los Angeles alone.
Far from being clinical, some feature carnivalesque hucksters who stand outside and lure in new clients. And pretty much anyone claiming a headache can get a prescription.
As a horticulturist, I worry that these patients are using a garden-grown substance whose dangers are greater than its benefits. They are the subjects of a loopy social-policy experiment.
I do not propose denying medical marijuana to those in chronic pain from cancer, AIDS, or other ailments. Marijuana's value as a pain reliever, as well as its overall safety, deserves investigation. The American Medical Association has sensibly urged the federal government to loosen restrictions that impede serious research. But right now, the scientific findings are far from conclusive.
Yet the same people who want their food grown organically and sustainably — and who flee from corn syrup, butter, and salt as from a plague — blithely ignore pot's provenance. They seem indifferent not only to where it comes from, but to who sows and grows it, and what manner of fertilizers, herbicides, pesticides, and growth stimulants are used.
Today's pot is far stronger than the weed that gave young boomers a buzz. Those seeking pain relief from a few puffs of marijuana can experience anxiety, panic, and hallucinations. Some help!
While there is limited evidence to support marijuana's medical benefits, there is plenty confirming its dangers, substantiated by significant increases in mentions of marijuana as a reason for emergency room visits over the last 15 years. And pot messes with your head, impairing short-term memory, verbal skill, judgment, and perception. Anyone who's talked to a pothead will testify to that.
Pot-using teenagers have poorer grades and poorer attendance. One study found that among those arrested, 41 percent of men and 27 percent of women tested positive for marijuana use. Another found that 6 to 11 percent of fatal-accident victims tested positive for it — a painkiller indeed.
Since pot's potency can vary dramatically, patients have no guidelines for dosage, so you might say it's hit or miss. This and many of marijuana's other perils can be effectively addressed by Marinol, an approved prescription medicine that offers calibrated doses of a synthetic version of pot's key ingredient, THC.
Medical marijuana deserves serious attention from the Obama administration, Congress, the FDA, and the AMA. What are they waiting for? Unchecked, this latest extraordinary popular delusion will have serious social and medical consequences.