With marijuana legalization initiatives on the ballots in three states on Nov. 6, we thought it would be timely to get a doctor’s opinion on cannabis in all its glory — its medical benefits, its down sides, and its proper place in the panoply of controlled substances.  For that, we turned to Dr. Benjamin Nordstrom,  the Director of Addiction Services at Dartmouth Hitchcock Medical Center, and Assistant Professor of Psychiatry at the Geisel School of Medicine at Dartmouth.  Dr. Nordstrom’s very distinguished credentials can be found here.

Q: From a doctor’s perspective, what medical benefits does marijuana provide, if any?  What diseases or symptoms is marijuana best suited to treat?

A: So far we have good evidence that delta-9 THC, a cannabinoid, and the active ingredient in marijuana, is effective in
treating chemotherapy-induced nausea and in stimulating appetite in patients with AIDS who cannot bring themselves to eat and are literally wasting away.  This substance, under the name dronabinol, or Marinol,  has already been FDA approved for use in these two conditions.  We also know that THC can have pain-relieving effects, especially for people with multiple sclerosis.  In addition, there are many other cannabinoids in marijuana that might have medicinal use, and there are literally hundreds of synthetic cannabinoids that show promise for medicinal properties.

Q: Advocates of medical marijuana statutes argue that marijuana should be rescheduled under the federal Controlled substances Act from Schedule I (no established medical use) to Schedule II (established medical use; may be prescribed by a doctor), to enable states to decriminalize marijuana for medical use without federal interference.  In your opinion, has the medical efficacy of marijuana been sufficiently established by studies to allow for this?  If not, what further studies do you believe are needed to assess marijuana’s medical uses?  Are there roadblocks to completing such studies?

A: I think there are few, if any, physicians or medical researchers who would argue that there are no therapeutic possibilities
for cannabinoids.  The question isn’t whether these are therapeutically useful compounds- it’s which ones, at what dose, delivered by what mechanism and for what specific conditions.  For example, no one would argue that morphine isn’t an effective pain medication or cough suppressant.  This, however, doesn’t mean that smoking opium is the medically appropriate way to deliver morphine.  No studies have been done that show that smoked marijuana (which is Schedule I) is superior to other THC delivery mechanisms (such as taking dronabinol pills, which are Schedule III).  Moreover, there is no place in modern medicine where we advocate people use a raw plant product in lieu of more precise dosing with a refined medication.  We don’t have people smoke or drink opium gum, chew coca leaves, gnaw on a quid of ma huang leaves, eat foxglove or chew on yew bark or birch bark.  All of these botanical products produce useful drugs which we refine and purify prior to studying them scientifically and then incorporating them into medical practice in an evidence-based manner.

Certainly, our politics shouldn’t make us blanch from investigating marijuana and the cannabinoids as useful medications.  There should be basic science and pre-clinical studies to guide which substances are studied and for which conditions.  These substances should then be rigorously tested by our existing process of Phase I, II, and III clinical trials where their safety and efficacy are established under randomized, double-blind conditions.  I am perplexed why the pro-marijuana advocates are so desirous of selectively abandoning this tried-and-true approach only for this one drug.  The last time the ballot box was used to bypass the scientific approach to medication testing was with a compound called laetrile.  Here, public sentiment and hype led to the legislative approval of a medication made from peach or apricot pits as a cancer remedy despite the lack of any scientific data it was safe or effective.  Later, it was found to produce cyanide poisoning in people.  The laetrile case goes to show that just as politics shouldn’t preclude scientific inquiry, neither should politics subvert scientific inquiry.  The push for “medical” marijuana is happening in a near vacuum of sound scientific evidence of its safety or efficacy.

Q: Cocaine is currently a Schedule II controlled substance, and many advocates of medical marijuana laws point to this as an
anomaly.  How do marijuana and cocaine compare in terms of medical uses and detrimental effects?

A: Cocaine’s medical use is as a topical anesthetic and vasoconstrictor (meaning it can reduce bleeding of superficial blood vessels), much like lidocaine or Novocaine.  Recreationally, cocaine is snorted, injected, or smoked.  The comparison to marijuana is a bit spurious, as no one ever abused cocaine topically, while smoked marijuana is the main modality of recreational use.  In fact, I think the cocaine example proves the effectiveness of the scientific approach.  We found
that the extract of coca leaves (cocaine) had legitimate medical uses for eye surgery and ear-nose-throat surgery.  Early on, it was tried in a number of conditions such as morphine addiction, nervous exhaustion, and hay fever. When it became clear that cocaine was unsafe for use in these conditions, its use was restricted, but the proverbial baby was not thrown out with the
bathwater and it remained available for certain clinical instances. It is available in a purified form that works effectively and with no abuse potential ( i.e. in a dilute solution that is applied directly to the area involved and not given systemically).  This careful approach allows a non-proprietary compound with severe abuse potential to be safely and humanely used to the benefit of those who need it.  I think this is the very model that marijuana should follow.

Q: What are the negative attributes of marijuana from a medical perspective?  Are there neurological or physical side effects that should be part of the decriminalization debate?  Do the negative effects vary with age?

A: There has been a lot of hype and hysteria from the pro and anti-marijuana camps.  Marijuana is clearly not “the devil’s weed” nor an “assassin of youth”, and attempts to overstate the danger it poses have only served to discredit the anti-marijuana advocates.  That said, marijuana isn’t just a harmless plant capable of producing only good in the lives of those who use it.  THC is an intoxicant that activates the same brain reward circuit as any other drug of abuse.  It produces an addiction in approximately 10% of people who try it.   People who are addicted to marijuana are only able to stop at rates similar to people trying to quit other drugs, and studies have shown that marijuana addiction can cause just as many problems for people as any other drug addiction.  In addition, there is an open question about whether marijuana use increases the likelihood of developing a psychotic illness, like schizophrenia.  A strong correlation between marijuana use and psychosis has been noted, but this
does not imply that one causes the other.  Similarly, the younger a person is when they first try marijuana, the more likely they are to use other drugs.  Again, it would be spurious to conclude that one phenomenon causes the other.  While the large majority of people who use marijuana don’t, and won’t, have a problem with it, will cause real damage in the lives of a substantial minority of marijuana users.  If the number of people using marijuana in the population increases due to decreasing prohibitions, the total amount of harm caused by marijuana use will also rise.

Q: For states considering decriminalizing marijuana for recreational use, what concerns would you as an addiction specialist
raise?  How should these concerns be reflected in laws?

A: As an addiction specialist I would have very little concern about decriminalizing cannabis, and no concern whatsoever about
de-penalizing cannabis use.  The studies that have been done have shown that decriminalizing cannabis does not really lead to increased cannabis use, or to new users being recruited into cannabis use.  I have much graver concerns about the legalization of cannabis.  Once a drug is legal, it can be commoditized.  In the Netherlands, use of cannabis didn’t increase among adolescents until cannabis sellers began to advertise their product.  If marijuana were legal, we could see advertisements for it like we do for tobacco and alcohol, both of which have dire public health consequences. If cannabis use increases, the public health consequences attendant to its use (even if these are less than those of alcohol) will increase as well. Keeping marijuana illegal gives us the best hope at limiting its public health costs, but it is also absolutely imperative that the sanctions for use are not disproportionate, expensive, inefficient, or unjust. Given the state of the scientific evidence of marijuana’s medical utility, I think completely rethinking how we penalize marijuana use is a far more pressing issue with much greater immediate societal implications than fretting about its potential medical uses.