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Running Amok on Marijuana: Re-hashing the grain of truth in one of the world’s most persistent myths

Updated: Aug 29, 2023

by Nick Johnson, author of Grass Roots: A History of Cannabis in the American West (Oregon State University Press, 2017)


There’s no denying that the growing nationwide acceptance of cannabis in the twenty-first century has illuminated the many benefits of this plant, long-sequestered in American society:

Hemp, the non-psychoactive variety, is a multi-faceted crop with a bevy of industrial and consumer applications.

The many inter-working compounds in marijuana are an effective medicine capable of alleviating—and possibly curing—some of our most agonizing ailments.

Widespread use of marijuana has proven to be a relatively safe activity that has never produced a lethal overdose or lived up to its opponents’ worst fears.

Cannabis advocates revel in these facts; they form the backbone of the argument for legalization. But every so often a report comes out that notches a chink in activists’ rhetorical armor. In particular, several recent incidents reflect a darker, if relatively uncommon, strain in cannabis’s long history amidst human societies:

In April 2014, a Colorado man ate an edible, became irrationally paranoid, grabbed a gun and fatally shot his wife.

On July 6, 2017, a 23-year-old man ate an edible before his flight from Seattle to China. During a trip to the restroom mid-flight, he became inexplicably paranoid and angry. In his ensuing tousle with flight attendants and passengers, the man both gave and received wine-bottle blows to the head.

Earlier this month, in Racine, Wisconsin, a 23-year-old man became so paranoid after smoking a blunt that he repeatedly stabbed his mother, thinking she was about to rape him.

In the wake of these incidents, both advocates and the cannabis industry either ignored them completely or shrugged them off as exaggerative examples of modern-day Reefer Madness. But whether or not they were truly fueled by the herb, violent, psychotic outbursts have always cropped up in humanity’s millennia-old experience with cannabis.

The Herb that Runs Amok

In his 2012 book Home Grown, cannabis historian Isaac Campos sought to explain why many observers in nineteenth-century Mexico believed that marijuana led to violent outbursts, especially stabbing sprees. Campos’s research suggests that notions of “marijuana madness” in Mexico were at least partially grounded in far older, yet strikingly similar experiences in Malay society. In ancient Malaysia, an incident known as mengamok–“a furious and desperate charge”—occurred when an otherwise mild-mannered person suddenly embarked on a violent maiming or killing spree, requiring others to subdue and restrain him.

“Running amok,” as the phenomenon is now known, is not believed to be caused by a drug, but rather manifests as a symptom of a pre-existing mental illness. Marijuana has been observed to produce a temporary version of this psychosis in some individuals, which could plausibly account for some of the erratic and violent behavior in cases like the Racine stabbing and raucous China flight.

The sheer complexity of the issue prevented Campos from making a solid conclusion about marijuana and crime in early Mexico, but he presents enough evidence to suggest that observers wove a few legitimate instances of mentally ill people “running amok” on cannabis into a popular mythology about the drug, one that emphasized its purported ability to induce madness.

Mexican ideas of “marijuana madness” eventually made their way north into the United States, providing the foundation for the distinctly American myth of “Reefer Madness.” In his amateur history of marijuana in America, cannabis advocate Larry Sloman offers a compelling explanation for widespread reports of “running amok”-type incidents:

[I]ndividuals who were more prone to be violent for environmental or cultural reasons (i.e. lower-class people) were, in fact, the majority of users of the substance. … with a growing stream of propaganda shrilling about the crime-causing properties of the weed, a situation became ripe where to engage in criminal activities while under the weed might be to assert a self-fulfilling prophecy.

When we merge marijuana’s known tendency to produce temporary psychosis in some users with its well-documented effects on those with mental illness, and acknowledge that recent “amok” incidents are strikingly similar to other events documented by historians, a clearer picture of the cannabis-violence issue comes into focus. Today’s cannabis advocates would do well to take a close look at it.

Lessons for Legalization

If those in favor of cannabis legalization—myself included—are serious about creating an industry and culture that promotes safe, responsible consumption, we must take seriously the herb’s potential to create dangerous scenarios like the ones in recent reports. Failure to do so may play into the hands of those who wish to see cannabis re-criminalized. To see how this can happen, we turn to the work of yet another cannabis historian.


In Grass Roots: The Rise, Fall, and Rise of Marijuana in America, Emily Dufton points out that the shifting narratives surrounding cannabis have done more to drive major changes in marijuana policy than any set of facts about the plant. By the mid-1970s, Dufton writes, progressive activists across the country had successfully lobbied for decriminalization in several states, mostly by arguing that adults had the right to use intoxicating substances, especially one as mild as marijuana. Yet by the early 1980s, anti-pot parent groups had turned this narrative on its head, arguing that no matter what rights an adult had, the nation’s children had a right to grow up drug-free. Just when the country appeared to be on the cusp of national decriminalization, most Americans sided with the parents, shunting the pro-cannabis crowd toward the moral and political void.

Importantly, this shift in public opinion occurred despite the fact that a rigorous report from the Nixon Administration had already recommended decriminalization, and it occurred despite a plunge in youth drug use in the late seventies and early eighties. The fear that children were being exposed to marijuana trumped the fact that, increasingly, they weren’t.

The work of Dufton and other cannabis historians makes one thing very clear: If they want to secure their gains in the present, cannabis activists must learn from the past. They must recognize that by ignoring or downplaying incidents of weed-induced paranoia and violence, they not only perpetuate the myth that being pro-weed means being blind to the effects of drug use; they also open the door for anti-pot groups to seize on these stories, using them as rhetorical fodder to turn the tide of public opinion back against legalization.

Putting Lessons in Practice

Though they might not gain much traction now, such arguments will always surface in the aftermath of pot-related incidents. For instance, after the stabbing in Racine, Wisconsin, a member of the parent group The Addict’s Parents United (TAPU) wrote on Facebook, “There is NO SAFE Drug out there, anyone of them can kill..or put our kids in harms way along with others … even pot.” The first few comments on the post revealed the reflexive defensiveness that has become ubiquitous in the pro-cannabis community: “there had to be other issues,” one commenter wrote; “PCP laced,” wrote another, referring to the not-uncommon practice of lacing someone’s pot with a more powerful hallucinogen; a third commenter blamed “mold pesticides and fungus” in the marijuana.

In the wake of apparent or alleged pot-related violence, advocates should resist this urge to immediately barrel into a full-throated defense of the weed. Rather than deny or deflect charges that marijuana can induce psychotic or violent episodes, activists should confront and contextualize incidents like the Racine stabbing.

First, they should admit that, like all other intoxicants, marijuana use carries the risk of adverse reaction and behavior. Instead of launching into defensive rants, they must show empathy for the victims and observers who are concerned about the role that cannabis may have played in the incident.

Establishing empathy with victims and acknowledging the risks of marijuana use gives activists firmer rhetorical ground on which to lay out important context that reminds observers that marijuana is rarely associated with stabbings and other violent incidents. For instance, multiple studies over the last two decades suggest that individuals with a history of mental illness are at the highest risk of an adverse cannabis experience. Of course, dosage matters (especially with edible cannabis), but the vast majority of people who use the drug are, as Nixon’s Shafer commission concluded, no more violent than anyone else. Violent crime actually decreased in Washington and Colorado after both states legalized cannabis in 2012.

One can also point to obvious parallels in the alcohol experience. People routinely get too drunk and rowdy—even hurting or killing others—and awake to unpleasant, if entirely appropriate, consequences the next day. Does it mean said person is a lifelong criminal, or that the drug they ingested universally produces such behavior? Do observers see these incidents as grounds for the re-criminalization of alcohol?

In sum, a steady dose of context, as well as continued research and education—not blanket condemnation or scare tactics—are the best way to predict and address negative marijuana experiences. And legitimate research and education is only possible with the safe, controlled access and tax-funded initiatives provided by legalization.

But cannabis activists must remember that, no matter how many facts are on their side, they are ultimately at the mercy of their fellow citizens, many of whom do not use cannabis. When it comes to marijuana in the United States, the court of public opinion is easily swayed, and history shows us that it is most often a change of heart rather than a change of mind. For proponents of cannabis, success will likely come from appeals to both—even if that means facing down some of the seedier aspects of our favorite plant.



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