Scientific American 201907

10 Scientific American, July 2019

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COMMENTARY ON SCIENCE IN

THE NEWS FROM THE EXPERTS

Illustration by Jialun Deng

Jonathan N. Stea is a registered and practicing

clinical psychologist in Calgary.

Can Cannabis

Fix the Opioid

Crisis?

Not alone, but it could be part

of the solution

By Jonathan N. Stea

Cannabis has been hailed as a potential magic bullet in the
fight against all sorts of ills, including chronic pain and depres-
sion. But it has also been called the “devil’s lettuce,” with claims
that using it will lead to laziness, insanity and even murder.
These polarized views can, in part, be explained by the drug’s
complexity: cannabis is not a single substance but rather a mix-
ture of more than 500 individual chemicals whose proportions
vary from one plant strain to another.
Because cannabis is such a complicated chemical soup, until
recently most often prepared for the black market, it has been dif-
ficult to draw clear research conclusions about whether the sub-

stance harms or helps. This assessment is particularly true in the

area of addiction and mental health, where advocates believe that

the drug could be the white knight of the opioid epidemic.

Some U.S. states—New York, New Jersey and Pennsylvania—

have followed the lead of such advocates and explicitly approved

medical cannabis as a treatment for opioid addiction. But critics

of these policy decisions have argued there is not yet enough evi-

dence to support and promote cannabis as an effective panacea.

And the critics are correct: there have been no randomized con-

trolled trials—the gold standard for testing drug effects—that

have evaluated cannabis specifically for treating opioid addiction.

Further, as argued by Keith Humphreys of Stanford Universi-

ty and Richard Saitz of Boston University in JAMA, substituting

cannabis for opioid addiction therapies could be harmful because

it would displace already established treatments, such as metha-

done and buprenorphine—which could be life-threatening. At this

time, offering cannabis as a treatment for opioid addiction is not

consistent with the practice of evidence-based medicine.

But such evidence is beginning to emerge. A recent review in

Cannabis and Cannabinoid Research, for example, shows that

cannabis might be able to help with the treatment of opioid symp-

toms such as withdrawal and cravings. The reason: biologically,

the receptor systems in the brain that allow cannabis and opioids

to affect us are closely related. If the goal of treatment is to reduce

harm, then it makes intuitive sense to offer cannabis in the hope

that opioid use will decrease. Cannabis is less dangerous than illic-

it opioids to both the individual and society at large. While there

is a small chance that substituting a less harmful drug for a more

harmful one could simply lead to a new addiction, this approach

might well be a risk worth taking.

One issue complicates the equation: it’s unclear if cannabis can

help people who experience opioid addiction and chronic pain.

Whereas fewer than 8 percent of pain patients become addicted to

opioids, people addicted to opioids have higher rates of chronic

pain as compared with the general population. The

effectiveness of cannabis for pain management is by no

means proved: re search on this question so far is rela-

tively weak—but that could be said for most work on a

drug scientists have been discouraged from studying by

the government. The case is by no means closed.

So will cannabis be the cure for the opioid crisis? Not

by itself, clearly: the crisis is a multilayered and multi-

causal problem that demands a multipronged solution.

Because opioid addiction develops as the result of many

interacting biological, psychological and social factors,

effective treatment modalities are needed at each level

of analysis. This complexity suggests an ap proach that

incorporates evidence-based psychological and pharma-

cological treatments, coupled with a system that allows

people easy access, whether through family physicians,

emergency departments, pain-treatment centers, safe

injection sites, or outpatient and residential programs.

Despite the hype, it is absurd to think cannabis can

be a remedy for all aspects of the human condition.

There is, however, good reason to believe that future research

will support a helpful role for it in the treatment of opioid addic-

tion. But we are not there yet. This kind of work, especially in the

form of randomized controlled trials, is sorely lacking and ur -

gently needed. Such research should be aggressively pursued so

we can say with better certainty whether cannabis belongs in the

evidence-based tool kit in the fight against opioid addiction.

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