The epidemiology of major symptoms caused by cannabis use has become a lot clearer in the past 10 years. Thirty years ago there was an isolated study showing that army conscripts who were marijuana smokers were more likely to develop schizophrenia. There was also a prominent researcher at the time suggesting that populations where there were high levels of cannabis use did not have higher rates of psychosis. But those populations did not have high quality epidemiological data. The latest studies show significant increases in the likelihood of schizophrenia and mood disorders. I think that this probably happens in a minority of people and probably those consuming the most THC. There is a lot of discussion about the differences in THC content of marijuana in the 1970s relative to what it is now, but not much reliable data to back that up. Since THC is a pharmacologically active molecule with known pharmacokinetic properties it is always a question of dose as well as potency. Multiple doses will eventually get you to the same levels of fewer doses of a more potent product. he need to avoid positive urine toxicologies for THC also drives the market in synthetic cannabinoids, since the word on the street is that taking these drugs does not result in a positive toxicology screen and jeopardize employment.
A recent public opinion poll shows (click to enlarge). The recent trend to legalize comes in the context of an increasing trend about using marijuana and other controlled substances for legitimate medical purposes and media portrayals of marijuana as a source of employment, entertainment, and alternative medicine.
There is not the same level of skepticism about marijuana as there is about psychiatric medications. In that case, the drugs are approved as safe and efficacious by regulatory bodies. There is no evidence that they cause problems at anywhere near the level of marijuana and yet the latter is generally given a bye in the media. Incredibly, many states get around the legalization of a scheduled drug by making it a "medically necessary" substance. In spite of the fact that cannabis has been around for over 850 years and tens of thousands newer medications were invented and used successfully, the myth that cannabinoids are necessary as a medication has been promulgated in an apparent effort to increase the legalization of this substance. The Obama administration has taken a public stand on the medical marijuana issue saying that the state statutes stand, but that they will engage in a selective prosecution that targets organized and violent crime, especially if that crime involves children or increased access to firearms.
I think that medical marijuana is generally a concept that has little to do with medicine and more to do with the legalization of marijuana. It would become much more obvious if there were exposes in the press about how prescriptions for medical marijuana actually work. What has to be said in the interview to get the prescriptions and what are the incentives of these prescribers? We have had a fairly constant barrage of criticism of psychiatrists prescribing non-addicting drugs to patients for legitimate FDA approved indications that are in aggregate safer than cannabinoids. Where are the questions about an industry that is selling a potentially addictive drug that has no clear medical indication and the potential conflict of interest of the prescribers? I certainly have no problem continuing to advise all my patients with, anxiety, mood, addictive, and psychotic disorders that they need to not use marijuana at all, despite the fact that they are getting advice that marijuana is good for anxiety, depression, and insomnia. I also have no problem telling anyone who might want a medical marijuana prescription that medical marijuana is a political term that has nothing to do with the practice of medicine and as such - I am not a "prescriber".
The other physician dimension to this issue is overprescribing. The current epidemic of prescription opioid use and resulting accidental overdose deaths is a good example. Unlike marijuana, the opioids have clear indications for use and contraindications. In aggregate, marijuana probably has a wider safety margin, but the prescribing dynamic is similar to opioids and antibiotics. The physician is confronted with a highly motivated patient who wants to leave the office with a prescription and physicians have have varying levels of motivation and skill to deny a wanted but unnecessary prescription.
I have no problem with any state declaring marijuana or any cannabinoids legal for its residents to line up and purchase. Although marijuana promoters always give the message that it is safer than alcohol, it has the same general parameters of use and no real medical indication. I do have a problem with involving medicine in an experiment to legitimize it for just about anything. I also think that physicians should know better. We ran similar experiments for drugs with clear medical indications like opioids in the past century and they did not turn out well.
George Dawson, MD, DFAPA
American Society of Addiction Medicine (ASAM): ASAM Medical Marijuana Task Force White Paper.
Joseph Lee, MD on Marijuana Legalization and the Impact on Children and Adolescents.
Dr. Oz addendum:
An example about the type of information the public gets from the media can't get any better than this Dr. Oz episode "Is Weed Addictive?" on December 4, 2913. The full details are not really provided at this time. I saw a debate and one of the participants was Pamela Riggs, MD who provided standard information on the addictive properties of marijuana.
Dr. Oz posts additional comments on his blog and seems to confuse the issues of addiction, legalization, and medical use. After talking how it is going to be widely available he concludes:
"As the trend towards legalizing this drug continues, we need to be aware of its risks and teach our children its proper place, which is in the pharmacy, not in the kitchen cabinet and certainly not in the school locker."
So it will be more widely legalized as a pharmaceutical that people will use that way?
I will post additional details of this broadcast as they become available.