Thought Broadcast

Is marijuana really medicine?  I’m not arguing against the potential for marijuana to treat illness, nor do I mean to imply that marijuana is simply a recreational drug that has no place in medicine.  Instead, I simply wish to point out how the “medical” label, I feel, has been misused and co-opted in a way that reveals what “medicine” really is (and is not).

Let me state, for the record, that I have no position on medical marijuana.  I practice in California, a state in which it is legal to use marijuana for medicinal purposes.  Even though I do not prescribe it, I do not judge those who do, nor those who use it.  I agree that it can be helpful in a wide range of illnesses– sometimes even in the place of established medicines.  It is unfortunate that controlled studies on THC and other cannabinoid compounds– studies that could lead to new therapies– have not been performed.

Medical care usually follows a well-established outline: a patient with a complaint undergoes an examination by a provider; a diagnosis is determined; potential courses of treatment are evaluated; and the optimal treatment is prescribed.  Afterward, the patient follows up with the provider to determine the efficacy of treatment, any potential side effects, and interactions with other medications or therapies.  The frequency of follow-up is determined by the severity of the illness, and therapy is discontinued after it is no longer necessary, or becomes detrimental to the patient.

Unfortunately, none of this describes how medical marijuana is practiced.  Any patient can undergo an examination; the vast majority of such patients have already been using marijuana and explain that they find it helpful, and the provider issues a card stating that they “advise” the use of medical marijuana.  Not a prescription, but a card– which permits him or her to buy virtually any amount, of any type of cannabis desired.  Follow-up visits are typically yearly, not to evalaute response to treatment, but to issue a new card.

As a psychiatrist, I frequently see patients who tell me they have been prescribed marijuana for “anxiety” or “depression.”  Often, my evaluation confirms that they do indeed suffer from, say, a clinically relevant anxiety disorder or major depression.  However, when I know they are using another chemical to treat their symptoms (whether cannabis, alcohol, or a medication prescribed by another physician) it becomes my responsibility to determine whether it will interfere with treatment.  In most cases, it also makes sense to collaborate with the other provider to develop a treatment plan, much as a cardiologist might collaborate with a family physician to manage a patient’s coronary artery disease.  [Sometimes the treatment plan might be to continue marijuana because I believe psychiatric meds simply won’t have any effect.]

But efforts to communicate with marijuana prescribers often fail (and when I have been successful in communicating with such a prescriber, they’re usually surprised that I made the effort!).  Similarly, if I suggest to a patient that he or she consult with the marijuana prescriber to find a strain, or a delivery method, or a dosing interval, that would provide the best symptom relief, or the least interaction with conventional medications– they often react with shock.  “But I only see him once a year,” is the answer I receive.

Often I say to myself something like, “well, marijuana helps him, so I’ll let him continue using it; I’ll just ‘work around it’ unless it becomes a problem.”  The patient usually tells me that he wants to continue using marijuana “as needed,” but he also wishes to continue in treatment with me, taking the medications I prescribe and following through with any treatment I suggest.

It leads to an uncomfortable compartmentalization of care, in which I feel that I’m practicing “real” medicine, while simultaneously condoning his use of another substance, even though neither of us knows the true chemical content of this substance, doses might vary from day to day, and some might be shared with friends.  To top it all off, patients frequently report a greater response to marijuana than what I prescribe, and yet I ignore it?  This is not the way I was trained to practice medicine, and yet I do it almost every day.

The approval of “medical marijuana” has been, I believe, a successful campaign by proponents of marijuana legalization to take advantage of the fragmented and confused health care system to create a de facto social sanction of marijuana use, rather than (a) introducing it as a true “medicine” through the proper and accepted channels (clinical trials, FDA approval, etc) or (b) decriminalizing it into a legal drug, much like alcohol.  I can see the arguments in favor of either approach, but the “medical” label unfortunately undermines what we actually try to do in medicine.

On the other hand, if it works, maybe we ought to take a closer look at what we actually are trying to do in medicine.  If medicine worked all the time, there would be no need for medical marijuana, would there?

Are people with mental illness more violent or aggressive, or more likely to commit crimes than those without mental illness?  Two recent papers investigate different aspects of this question.

In the January 2011 issue of Psychiatric Services, Fisher and colleagues investigate data from the Massachusetts Department of Mental Health, and found that people who had been diagnosed with a “severe and persistent psychiatric disorder” were two-thirds more likely than the general population to be arrested within a one-year period.  Arrest rates were significantly higher for all crimes, but particularly high for assault and battery on a police officer, a felony (odds ratio 5.96, or about 6 times more likely), and “crimes against public decency” (odds ratio 4.72).  While the data only reflect arrests (and not convictions, which would be fewer, since some charges were undoubtedly dropped), and say nothing about whether a person was actively involved in treatment at the time of his or her arrest, it does portray the severely mentally ill as more likely to engage with the criminal justice system.

A separate study, published last month in PLOS One, examined reports of medication-related adverse events to the FDA.  The authors looked at 484 drugs and the rates with which they had been associated with “violence-related symptoms.”  All medications had some such symptoms reported, but certain classes of drugs were associated with more frequent violent events than would occur by chance alone.  In particular, varenicline (Chantix) was most frequently associated with reports of violence, with a PRR (proportional reporting ratio) of 18.0.  (This means that the proportion of violent events by patients on Chantix was 18 times greater than the proportion of violent events reported for all other drugs).  Other medications shown to be associated with violent behaivor included antidepressants (average PRR = 8.4) and psychostimulants (average PRR = 6.9).  

It should be pointed out that the authors of the PLOS study have served as expert witnesses in criminal cases involving psychiatric drugs, and work for the Institute for Safe Medication Practices, a nonprofit group dedicated to exposing medication risks.  Furthermore, the reports of adverse events to the FDA may suffer from “attribution error”: when an adverse event like a violent act occurs, we search for possible causes, and medications– particulalry psychiatric meds– are frequent culprits, when in fact there may be no causal relationship.  Nevertheless, the large numbers of events, and the relative consistency within drug classes, should give us reason for concern.

But even with these limitations, these studies unfortunately show that criminal activity may indeed be more common among the mentally ill, and we need to exercise caution when using medications when the risk of aggression is high, to avoid making matters worse.