Media Circus

Reporters were apparently too stoned to question two hopelessly flawed studies "proving" that marijuana is a gateway to heroin.

By Cynthia Cotts
Published August 18, 1997 7:00PM (EDT)

there's a new campaign to call marijuana a hard drug -- and once again, the press is contributing to the hype.

At the heart of the campaign are two studies on the neurochemical effects of THC, marijuana's effective ingredient, published recently in Science magazine. The putative results: Marijuana is not only a "gateway" drug to heroin, but addictive in its own right. Just like alcohol and cocaine, marijuana is capable of "hijacking the brain's so-called reward system," Science reported, and priming it for future addiction.

These bold claims were publicized in a press release by the National Institute on Drug Abuse and subsequently reported by newspapers across the country. "Studies back gateway role of pot," said the Los Angeles Times, while USA Today took the other tack: "Marijuana's active ingredient may cause addiction."

Although Science cautioned that "More work will be needed to confirm these ideas," the mainstream media parroted NIDA's spin on the story. Only Newsday bothered to quote independent researchers who found the data less than compelling. And despite disclaimers that they had no direct evidence, two of the scientists involved were eager to simplify matters for the press. "I would be satisfied," Gaetano di Chiara of the University of Cagliari in Italy told a reporter, "if, following all this evidence, people would no longer consider THC a soft drug." George Koob, from Scripps Research Institute in California, chimed in, "We're blurring the line between hard and soft drugs."

The marijuana-heroin link is an old saw. But this summer, when confronted with studies using pharmaceutical analogs and fancy brain dialysis, the reporters were either too lazy or too loathe to question the hype. Moreover, the media failed to report that the new studies are being promoted by the same government that is busy fighting California and Arizona's successful grass-roots campaigns to allow marijuana to be used for medicinal purposes. Given the shaky status of U.S. drug policy, it's quite possible that a Clinton operative asked NIDA to put the spin on two inconclusive experiments and rush out a press release. After all, as Nixon's National Commission on Marijuana noted in 1972, "Science has become a weapon in a propaganda battle."

The policy of distorting the pharmacological effects of marijuana became official in 1970, when Congress passed the Controlled Substances Act, classifying marijuana as an illegal drug with no medical value. Safely out of reach of the hoi polloi, cannabis was turned over to scientists. In 1973, NIDA began funding every type of cannabis research, with one exception: Scientists wishing to prove that marijuana is a safe and effective medicine need not apply.

The media rarely reports on a notably lucrative corner of the cannabis business: the secret labs where technicians inject dogs, monkeys and mice with massive doses of synthetic THC, in order to provoke harmful results. For example, you may have heard the conclusion that marijuana impairs the immune system, but you probably haven't read about the evidence that is often used to support it: In the mid-1980s, researchers injected female guinea pigs with THC, and then smeared the herpes virus directly on their genitalia.

The drug warriors' latest canard -- that marijuana is addictive -- is so novel that it wasn't cited in 1992, when the Bush administration closed down its experimental medical marijuana program. NIDA studies have failed to prove addiction in people who smoke marijuana, because natural THC takes so long to be excreted that it doesn't provoke withdrawal. Given that rats don't sit around passing a joint, the latest studies inject them with pure pharmaceuticals -- a sure-fire recipe for addiction, either in mice or men.

Rats and humans have one thing in common. Their brains produce the neurotransmitters dopamine and corticotropin, which are now all the rage in addiction studies. Dopamine is released in response to pleasurable activities, which include hitting a home run, listening to Mozart and french-kissing as well as drinking vodka and snorting cocaine. Corticotropin, which is linked to stress and pain, is released by animals going through withdrawal. Thus, when the authors of the new studies set out to prove that marijuana is addictive, they did so by getting rats high, then measuring the dopamine and corticotropin in their brains. They used a process called intracranial microdialysis, which means tying the rats down, cutting through their skulls, and inserting probes into their gray matter.

In the dopamine study, scientists at the University of Cagliari managed to give the rats enough THC to release dopamine in the pleasure circuits in their brains. Earlier THC studies had failed to "induce that telltale dopamine rush," as Science put it, but this one did, which made it a breakthrough. The study followed this line of logic: A) Addictive drugs trigger dopamine release. B) THC triggers dopamine release. C) Thus, pot-smoking may prime the brain for heroin addiction.

Now, any reporter worth her salt should be able to spot the faulty logic in that equation. But more importantly, it would only take that reporter a few minutes to call the press office of one of the many drug reform organizations, say she's on deadline and get the number of an expert on addiction studies. By doing so, she would learn that the NIDA press release had conspicuously singled out marijuana as a stepping stone to heroin. As Time magazine recently reported, most drugs, including alcohol, nicotine, opiates and tranquilizers, send dopamine racing down the pleasure tracks in the brain. If any dopamine trigger leads to heroin, then today's Ritalin-and-Budweiser kid may be tomorrow's junkie.

The corticotropin study, funded by NIDA and conducted at Scripps Research Institute and Complutense University in Madrid, was designed to prove the addiction theory once and for all. You wouldn't know it from reading the clips, but they had a major hurdle to overcome: Rats hate pot. In repeated studies, NIDA researchers have never been able to get rats to self-administer THC. So the Scripps guys took no chances. They hired a team of rats, strapped them down and gave them daily injections of THC for two weeks. When the party was over, they injected a blocker, which strips THC out of the brain receptors, and sat back to watch. For over an hour, the rats went through what looked like a classic kick (face scratching, pawing at ground). At the same time, researchers found traces of corticotropin in the rats' brains -- which, they admit, could have been caused by the stress of immobilization.

OK, so the corticotropin study engineered a situation in which THC withdrawal mirrored the effects of heroin withdrawal. But so what? Why didn't the reporters quote the fine print in the report, where the scientists admit they had no "direct evidence" to call marijuana a hard drug? Why didn't they point out the long leap from lab rats going through forced pharmaceutical withdrawal to people who smoke when they feel like it? We've long known that everyone reacts to drugs differently and that the risk of addiction is predicted by many factors, such as genetic hard-wiring and social status.

The more we learn about human brains, the more it seems we are all extraordinarily receptive to psychoactive substances. Given the rampant availability of drugs in America, there is no question that kids today run a high risk of becoming addicts. What to do? Given the laziness of the mainstream press, the best solution may be that offered by William Burroughs: Americans must volunteer to have the drug receptors in their brains removed, or else sacrifice all their civil liberties.

Cynthia Cotts

Cynthia Cotts is a New York writer who has written widely about media and drug policy.

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