California is the most populous of the five states to be considering the legal, controlled sale of recreational marijuana at next week’s general election. While Nevada, Arizona, Maine and Massachusetts will also be voting on state control of cannabis for recreational purposes, Arkansas, Florida, Montana and North Dakota will be voting on the medical use of marijuana.
Currently, 24 states and the District of Columbia have legal channels for the medical use of cannabis while four (and D.C.) allow limited sale and use of marijuana for recreational purposes.
In California, the proposed 62-page law (PDF) is formally known as the Control, Regulate and Tax Adult Use Act, or the Adult Use of Marijuana Act or, simply, Proposition 64. The highlights are fairly typical of those of the other states: allowance of up to one ounce of marijuana flower or eight grams of cannabis concentrates for adults age 21 and older, the personal cultivation of up to six marijuana plants, the industrial cultivation of hemp. But the taxation and regulatory apparatus would be somewhat more complicated than in other states.
My scientific interest in the therapeutic uses of marijuana stems from my academic career as a natural products pharmacologist. While my lab worked with chemists to characterize anticancer drugs they isolated from plants, fungi and cyanobacteria, my teaching requirements led my continuing education on other drugs from nature. Most of these turn out to be drugs often used for recreational purposes–opioids, cocaine, mescaline–so I’ve often turned to my neuroscience colleagues for professional guidance on the pharmacology of such substances, including their relative risks and benefits.
So it was fitting that I’ve been following a drug abuse researcher who currently works at the Scripps Research Institute in La Jolla, California. Michael Taffe, PhD, and his laboratory group have been funded by the National Institute on Drug Abuse (NIDA) to study the behavioral toxicity of drugs that are misused recreationally, including marijuana, ecstasy (MDMA), methamphetamine, substituted cathinones (the substances found in so-called “bath salts”) and alcohol.
As he lives in a state that will be influenced by the outcome of the Proposition 64 vote, Dr. Taffe posted some of his personal thoughts on Facebook, saying, “As many of my friends, neighbors and acquaintances are aware that I work in the substance-abuse fields of science, they have questions. So I thought I would put some of my usual responses/points down on a Fb post.”
I’ve always been impressed with Dr. Taffe because he views his role as a researcher to also include being an objective educator and information source for the public. As he writes:
First, some background on my opinions. I work for you, the taxpayer of the US. This is because my work is funded by grants from the National Institutes of Health. Because these are primarily from the National Institute on Drug Abuse, my role is to investigate the effects of recreational drugs on the brain (and the rest of the body) with some attention paid to how this might affect the health of humans.
This is most emphatically not a policy role. I have no special expertise on public policy and my comments are not meant in that way. I do hope that science can be used to inform policy and, frankly, I wish that public policy across the board paid a lot more attention to facts and data. This is not to say, however, that I believe that the facts necessarily lead all interested people to the same *policy* decision. Because policy requires the weighing of factors and pitting positives and negatives of various kinds against each other.We’ve been bantering over the last week or so about his thoughts, and I found them important enough to share them with you as they are certainly deserving of a wider audience and, moreover, are relevant to those of you in the other four states that are considering the sale of marijuana for recreational purposes.
For the sake of disclaimer, I should note that these thoughts come from Dr. Taffe as a neuroscience and psychology expert and that his opinions do not necessarily reflect those of the Scripps Research Institute or the NIH’s National Institute on Drug Abuse. Wherever possible, he has provided me with additional links to the primary scientific literature to support his thoughts and provide you with additional reading if you have more than a passing interest in the topic.
As far as legalizing recreational marijuana goes, I do think that the epidemiological, human laboratory and animal laboratory data has some relevance to the Prop 64 issues. So, I’m going to list a few facts.
1) Marijuana is addictive. Full stop. The conditional probability of dependence is about 9% where like-to-like comparisons put cocaine and methamphetamine at 15%, heroin at 25-45% (data are terrible) and alcohol at 4%. Alcohol is a huge problem because 85%+ of people consume it at least annually. In contrast, less than 1% of people have ever tried heroin, 0.4% in the past year. Marijuana comes in at about 32% annual prevalence for ages 19-28. The scope of the addiction issue depends on how many people are using it, obviously. This will go up with legalization–but we don’t have any idea how much.
2) 5-6% of high-school seniors use marijuana daily. Daily. That’s the U.S. average. I don’t have numbers for California.
3) Marijuana addiction is as “real” as any other. Frequency of withdrawal symptoms and severity of those symptoms were compared between marijuana and tobacco smokers and the data were nearly indistinguishable. Most people are much more familiar with nicotine dependency (which is a higher rate, by the way, probably 33%+) since it is more common, not embarrassing to discuss in public and conventionally recognized. A lack of personal familiarity with the scope of withdrawal in the people who are marijuana-dependent doesn’t mean that it doesn’t exist.
4) There is no such thing as “psychological” versus “physical” dependence since the brain is part of the body and the mind is the functioning of the brain. Keep in mind that people can be months to years out from their last use of any drug and still relapse severely. This is not being driven by the withdrawal symptoms that most everyone recognizes when they talk about “physical” dependence.
5) Marijuana acutely impairs cognitive and other behavioral functions.
6) Behavioral tolerance with chronic exposure is substantial. Blood levels of THC in animals or humans are a poorer proxy for impairment (versus other drugs) if you do not know anything about the prior exposure history.
7) THC is detectable in the body for a very long time compared with many other drugs of abuse. One study found detectable THC, or one of the main metabolites, for 30 days of inpatient study (chronic users).
8) Trying to make specific predictions about an individual who uses marijuana from general findings (there is always a central tendency or average around which the distribution of data points or individual outcomes varies) is a fools’ errand. We can only predict general trends. Conversely, and this is important for your personal introspection, the evidence from one given data point or individual doesn’t tell us much that is informative about the average trend. The fact that it is your personal experience does not make it more valid.
Dr. Taffe closes his comments saying, “Finally, there is much we simply don’t know. Any given scientific study or data set is limited by how it was generated. This doesn’t mean we throw up our hands and say it is all bunk or uninterpretable but it means one does have to think about it a bit.”
Lastly, he says, “I would invite you to read over the Prop 64 provisions. Personally, I see a fair bit of investment of the tax revenue in state sponsored activities to answer some of these issues better, to address some of the obvious concerns, etc. To me this is a positive. The extent to which this will happen, the extent to which actionable information will result, the extent to which activities intended to head off or ameliorate obvious negatives is, however, an unknown.”
No comments:
Post a Comment