A recent announcement from the U.S. Drug Enforcement Agency is good news for doctors starved for valid research on medical marijuana. The time has come for federal and state officials to step up and give more support to the kind of trials that will lead to answers on what this drug can do.

There is widespread medical consensus that the herb is useful, and public opinion is growing for the idea of giving patients a legal avenue for its use.

But in some ways the whole road to legalization seems to be proceeding in reverse. It has taken 23 states flouting federal marijuana laws — either declaring it medically useful or legalizing recreational use outright — before the DEA announced on Dec. 23 that it was relaxing regulations that had basically made clinical trials involving marijuana impossible.

That’s good news because it means we might finally be able to figure out how medically useful marijuana actually is. So far, the supporting anecdotal evidence is deafening — so loud it drowns out the reality.

And the reality is this: most doctors aren’t prescribing marijuana to patients where it is allowed.

New York’s fledgling medical marijuana program, which took 18 months to launch, is floundering. As of this month, only 166 patients have registered to receive medical marijuana and only 226 of the state’s 79,000 practicing physicians have become eligible to prescribe the drug. Critics have called the program overly-restrictive for both patients and doctors.

What about Colorado, though? That’s hardly a restrictive climate for marijuana. Last November, only 204 physicians — about 1.5 percent of the state’s doctors — recommended medical marijuana for patients, according to a Colorado Department of Health report.

None of that means medical marijuana is a sham. On the contrary, it underpins the conundrum facing doctors. Marijuana clearly has medical applications, but many doctors object to making a laboratory out of their waiting rooms, and turning their patients into test subjects.

A Brookings Institute paper on the issue sums it up nicely: “The use of cannabis for medical treatment is happening in states largely on anecdotal evidence or limited science ... patients and doctors operate according to a learn-as-you-go approach ...”

The Pennsylvania Medical Society, which opposes medical legalization for just this reason, last week sent a letter to the FDA, calling on state and federal officials to support more research on medical marijuana.

The letter also urged the FDA to reclassify marijuana as a Schedule II drug — something officials have been lollygagging over for decades — which would further enable research efforts.

Both the PMS and the American Medical Association oppose medical legalization, and have asked government officials to wait until more research can be conducted.

But waiting is becoming increasingly unrealistic. The tide of public opinion is rising, and claimed benefits to patients too great, to delay any longer. It’s also clear the federal government is either unable or unwilling to act on this issue unless its hand is forced by the states.

But the PMS and AMA stances, which don’t get much press, remind us that it’s not as simple as passing a law and passing out pot to doctors. Physicians — at least the responsible ones — want to know what they’re prescribing.

That’s going to take research, which will take time, money and government cooperation to complete. Until that happens, “medical marijuana” will be mostly style and little substance.

After all, what good is legalizing a drug that our doctors won’t prescribe?