So stated William C. Woodward, M.D., J.D., legislative counsel to the AMA,
in testimony in 1937 before the House Ways and Means Committee on the"
Marijuana Taxation Bill," which would have taxed physicians who
prescribed—and pharmacies that dispensed—cannabis.
(The bill passed, and in 1942 "cannabis" was officially removed
from the U.S. Pharmacopeia.)
Seventy years after Woodward's testimony, whether research has proven"
substantial medical uses" for cannabis—either smoked in the
form of the marijuana plant or taken in some other form—still appears to
be a matter of passionate debate.
Thirteen states have passed laws to make marijuana more accessible for
medical use. Many physicians and patients cite anecdotal evidence of the
efficacy of cannabis for chemotherapy-related nausea, AIDS-related wasting,
neuropathic pain, and other conditions; and a body of randomized controlled
trials exists—mostly with relatively small samples and short follow-up
times—documenting the benefits of cannabis for discrete conditions.
The American College of Physicians, among other groups, has called for
reclassification of marijuana under the Controlled Substances Act from a
Schedule I drug—under which it is deemed to have high abuse potential
and no proven medical uses—to another schedule that would make it more
available to researchers and clinicians.
On the opposing side are many physicians, including psychiatrists and
addiction specialists, who say that research on cannabis, especially its
long-term effects, is not sufficient to warrant rescheduling; that
legalization would lead to greater abuse—by nonpatients in the general
population, if not by patients; and that the medical community should proceed
with great caution before declaring marijuana "safe."
At the meeting of the AMA's House of Delegates last November, a resolution
to advocate for rescheduling marijuana was the subject of unusually lengthy
and passionate debate, only to be sent to the AMA's Council on Science and
Public Health for a report back to the House and the AMA Board of Trustees
(Psychiatric News, January 2).
Council chair and past APA President Carolyn Robinowitz, M.D., said she
could not comment on the issue prior to the council's deliberations except
that "there seem to be more opinions than data."
She said, "The council will look at the available evidence and
consider it carefully, and present—to the extent that it is
possible—an evidence-based report to the house."
To Sunil Aggarwal, Ph.D., the verdict is already in.
Aggarwal is a third-year medical student at the University of Washington
School of Medicine and a fellow in the Medical Scientist Training Program. His
doctoral dissertation, titled "The Medical Geography of Cannabinoid
Botanicals in Washington State: Access, Delivery, and Distress,"
discussed the successful use of medical marijuana or cannabinoid botanicals by
176 chronically and critically ill patients in Washington state.
(The term "cannabinoids" refers to any of the substances that
are structurally related to tetrahydrocannabinol, or THC, the psychoactive
ingredient in marijuana.)
At the AMA meeting, Aggarwal spoke to the Section Council on Psychiatry and
asserted that since 2001—when the House of Delegates last voted to
retain the Schedule I status of marijuana pending the outcome of
research—at least 10 randomized, controlled trials had been completed on
the use of cannabis for chronic neuropathic pain of multiple etiologies,
appetite and weight loss in HIV/AIDS, spasticity in multiple sclerosis, and
In each of these studies, researchers used a federal-government supply of
marijuana grown in Mississippi.
Aggarwal told psychiatrists at the meeting that the total body of
literature on the subject shows "that cannabinoids, of which cannabis
contains roughly 100 ... have activity at the body's cannabinoid receptors and
have many distinct pharmacologic properties, including analgesic, antiemetic,
antispasmodic, antioxidative, neuroprotective, antidepressant, anxiolytic, and
anti-inflammatory properties, as well as glial cell modulation and tumor
The 10 randomized controlled trials published since 2001 have relatively
small numbers—four had sample sizes of under 20 subjects, and the
largest had 62. And all were looking only at acute effects.
A meta-analysis of studies looking at longer-term effects published in the
July 2003 Journal of the International Neuropsychological Society
found that few studies on nonacute neurocognitive effects met current research
standards, but the studies that do exist suggest neurocognitive risks may be
"Our results indicate that there might be decrements in the ability
to learn and remember new information in chronic users, whereas other
cognitive abilities are unaffected," the analysis concluded."
However, from a neurocognitive standpoint, the small magnitude of these
effect sizes suggests that if cannabis compounds are found to have therapeutic
value, they may have an acceptable margin of safety under the more limited
conditions of exposure that would likely obtain in a medical
But for addiction psychiatrists like Stuart Gitlow, M.D., M.P.H., the
question is far from resolved. "Do the benefits outweigh the
risks?" he asked in an interview with Psychiatric News."
We don't have anything in the literature to suggest that the answer is
yes. None of the damage that has been shown to result from marijuana use is
evident in a short-term observation."
Gitlow said he is not opposed to marijuana's being used individually in
discrete situations, such as end-of-life care. But the question of legalizing
marijuana for medical uses, he said, cannot be disentangled from the larger
social context in which marijuana is widely used—addictively by
many—for recreational purposes.
He added, "At the individual level, there may not be a problem, but
when you look at it from a population basis, it's a different story. We know
from experience that when opioids, stimulants, and sedatives are present in
the home, they frequently find their way to people who aren't prescribed the
Yet the individual cases can be emotionally compelling. Said Aggarawal,"
If you see someone suffering from neuropathic pain and there is no
opioid that is helping, but you know that cannabinoids have a unique
therapeutic effect on this type of pain, are you going to let the person
suffer because his neighbor uses marijuana recreationally to enhance listening
to music? Morally, I fall on the side of treating."
On the question of whether legalization of marijuana for medical uses would
increase potential for drug abuse, a 1999 Institute of Medicine (IOM) report
(see IOM Report Still Sets Standard on Medical Marijuana) is agnostic."
[P]resent data on drug use progression neither support nor refute the
suggestion that medical availability would increase drug abuse," the IOM
The report also noted, "This question is beyond the issues normally
considered for medical uses of drugs and should not be a factor in evaluating
the therapeutic potential of marijuana or cannabinoids."
Perhaps the most enduring conclusion from the IOM report is the need for
more research—the one point on which everyone agrees. Gitlow said he
looks for some provision to make marijuana accessible to researchers without
changing the schedule status for the general population.
"We need controlled trials for an extended period of time, because
many of the effects are not going to show up in an eight-week trial,"
Gitlow said. "Ideally, this would be research in a controlled setting
without making the drug accessible to the public at large. The first step is
therefore to figure out the marijuana ingredient providing benefit and then
determine a safe method of dosing that ingredient. We can't jump to the end of
the process without first going through the necessary intermediate
An abstract of "Nonacute (Residual) Side Effects of Cannabis
Use: A Meta-Analytic Study" is posted at<www.ncbi.nlm.nih.gov/pubmed/12901774>.▪