Who Uses Marijuana for Medical Purposes?

January 9, 2017

Who Uses Marijuana for Medical Purposes?

  1. Peter Roy-Byrne, MD

People who report marijuana use for medical reasons are very similar to recreational users.

  1. Peter Roy-Byrne, MD

Over half of the U.S. states have approved marijuana for “medical” purposes, with three states joining the list after the November 2016 elections. Although limited evidence suggests that marijuana has analgesic effects (Clin J Pain 2013; 29:162) and could substitute for more harmful long-term prescription opioid use in individuals with chronic pain (J Pain 2016; 17:739), concerns remain that medicalization is often a gambit for legalized recreational use or that some patients use cannabis to “take the edge off” nonmedical distress. In contrast, adverse effects, especially with regular marijuana use (as is common in medical users), have been conclusively documented: harm to the adolescent brain, (J Neurosci 2014; 34:5529), reduced cortical gray matter in adults (Proc Natl Acad Sci U S A 2014; 111:16913), diminished cognitive function (Biol Psychiatry 2016; 79:557), and increased risk for psychosis (Lancet Psychiatry 2015; 2:233) and vehicular accidents (BMJ 2012; 344:e536).

A recent analysis of survey data on 96,100 adults in all 50 U.S. states further informs the debate (JAMA 2017; 317:209). Researchers compared the mental and physical health of past-year marijuana users (12.9% of participants) according to whether use was medical (0.8%), recreational (11.6%), or both (0.5%). Medical users and recreational users had similar rates of heart disease; hypertension; diabetes; asthma; hepatitis; HIV/AIDS; major depression; suicidal ideation; illicit-drug use disorders; use of tobacco, cocaine, hallucinogens, heroin, and inhalants; and nonmedical use of sedatives. However, compared with recreational users, medical-only users had higher rates of anxiety disorder, perceived poor health, and disability; reported lower use of alcohol and nonmedical use of stimulants and prescription analgesics; and were more likely to use marijuana daily. Less use of nonmedical prescription-analgesics might be consistent with use for pain. Higher anxiety rates could indicate periodic withdrawal reactions due to daily use, the development of anxiety resulting from regular use, or perhaps heightened emotional distress due to poorer health, suggesting that use may be directed at relieving distress rather than treating specific medical conditions.

These findings are consistent with those from earlier, smaller studies. One that I published last year (Am J Addict 2015; 24:599) documented poorer perceived health status, more pain, and greater physical disability in medical vs. recreational users, although the effect size was small. The only differences in medical illness were greater rates of connective tissue/skeletal disease and cancer in medical users. Similar proportions of medical and recreational users used ≥2 other illegal drugs (48% and 58%), although medical users were less likely to have severe drug problems. My conclusion from these studies: Medical and recreational users had many more similarities than differences, and the differences were small, suggesting that only a few “medical users” were likely targeting medical conditions.

One can imagine cancer sufferers using marijuana for nausea and pain, and chronic pain sufferers unable to wean themselves from prescription opioids substituting marijuana. But one can also imagine many others using marijuana as a rapidly acting, anxiolytic, and antistress medicine similar to a benzodiazepine — without randomized, controlled evidence of efficacy, knowledge of dosing strategies, or understanding of long-term adverse effects, tolerance, and withdrawal phenomena and mechanisms.

Longitudinal evidence is contradictory regarding whether marijuana use increases the risk for subsequent anxiety or mood disorders (BMC Psychiatry 2014; 14:136; JAMA Psychiatry 2016; 73:388; and Psychol Med 2014; 44:797). Still, cannabis use might adversely affect people who already have symptoms of anxiety and depression. In my practice, users already suffering from these symptoms experience further harmful effects that uniformly improve with cessation of the drug. Although animal models show that the endocannabinoid system is involved with stress and anxiety reactions, there is no human evidence that plant marijuana treats these conditions, especially as various cannabinoids can have opposing actions.

Until solid research can clearly identify whether and to what extent marijuana has medical benefits, anecdote and emotion may continue to drive the behavior of patients, doctors, and state legislatures. I strongly suggest that physicians pursue standard medical approaches before considering medical use of marijuana. In my practice as a psychiatrist, there are innumerable, evidence-based pharmacotherapies and psychotherapies for emotional distress. The rapid-acting nature of marijuana, along with its relaxing and euphoric effect, is clearly seductive for patient and doctor alike, but its long-term effects are unpredictable.

Editor Disclosures at Time of Publication

  • Disclosures for Peter Roy-Byrne, MD at time of publication Equity Valant Medical Solutions Grant / Research support NIH–National Institute of Mental Health Editorial boards Depression and Anxiety; UpToDate Leadership positions in professional societies Anxiety Disorders Association of America (Ex-Officio Board Member); Washington State Psychiatric Society (Immediate Past-President)

Reader Comments (5)

Parker, Cj Medical Student, Neurology

Tylenol is p450 enzyme blocker. Tylenol keeps cannabinoids (exogenous and endogenous) active longer. (Anandamide/THC) Thus, the serotonin depletion can be treated via the endocannabinoid route instead of the serotonin route alone. some just skip the serotonin modulators and use cannabis instead ( a more synergistic route). The problems lie in finding the right strain (there are thousands) to match with the right patient. PTSD marijuana users who run out of marijuana use Tylenol to step through the first four days until endogenous cannabinoids come back into full production, but if there is deficiency, supplementation is daily. If we used whole plant medicine correctly, there would be no need for the majority of synthetic versions but that would put your favorite pharma rep out of work if everyone was allowed to plant their own medicine.

Ron Wolf, MS CS Other, United States

Informative article, interesting & topical. Stats regarding Cannabis related health issues (or lack of) are far and few between. However, the article would more properly be titled "Comparison of Medical & Non-Medical Marijuana Users" as there seems to be nothing comparing Medical Marijuana Users with the general population? Or did I miss this?

Then, I might ask can one compare evidential quality from funded drug studies of limited size (even if several thousands) with observation of consumption in in the tens of millions in the general population?

Also, regarding commenting in general on jwatch, there is no Professional Specialty selection for Health Informatics (or similar) subtlety disenfranchising of those who are value your excellently curated content but are not hands on practitioners.

Charles Weber, D.O. Physician, Psychiatry, Private Practice

It is unfortunate if the personal and myopic view of those physicians with pedigree discount peer reviewed studies and articles.
If they believe that marijuana has so many benefits why not publish against the peers and have a valid, reproducible, statistically significant article?
The problem is that it is difficult to study because of its DEA classification and the inconsistent / variability among the type of cannabis / cannaboids.

Although great marketing and "grassroot" support we are still in the Egyptian / willow bark era of the potentials. But discounting the risks and harmful effects that occur for those daily users would be tragic and a departure from our "First do no harm." I have not seen anyone addicted to an SSRI, save the slight serotonin withdrawal headache that passes with Tylenol and time...this cannot be said of daily long term marijuana users.

Gary Maltz, MD FACP Physician, Internal Medicine, United States

The author references his article from the Am J Addict in 2015 in which at least half of both medical and recreational users used 2 or more other illegal drugs. Given that, I really wonder if the conclusions drawn are generalizable. I'd also be interested to know where the survey data on the 96,100 adults was drawn from.

JORDAN TISHLER Physician, Internal Medicine, InhaleMD

Once again the fox is guarding the hen house. As a psychiatrist, one sees the small handful of patients (7-9%) who develop difficulties with Cannabis use. Let's remember that that means you don't see the 90+% who do not, and who get real, sustainable relief from their symptoms. Let's also consider the harm potentially caused by the conventional medications that you profess should remain first-line: opiates 25%, benzos 18% (and that's just dependence rates, not withdrawal morbidity, or mortality). Even SSRIs have sig side effects: ahendonia, weight gain, sexual dysfunction.

It is my contention that until we stop having such literature reviewed by addiction specialists and by academics in particular, we'll never recognize the true benefit Cannabis provides.

I am a Harvard Internist. I have come to be a Cannabis medicine specialist, only after years of convincing by seeing the harm caused by other medications, and by seeing first-hand the benefit to patients from Cannabis used properly. I believe that Cannabis is a great tool for patient care when applied with a standard of care like any other medication.

Please consider the old adage, "If you're a hammer, all the world looks like a nail." While this could be applied to me as well, at least I am looking at the whole iceberg, not just the 7-9% above the waterline. Please get someone who actually knows Cannabis as medicine to review these studies.

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