Man rolling Marijuana joint
Credit: Martin Alonso/Flickr

In 2014, Maureen Dowd devoted a New York Times column to the story of her own ill-fated experiment with edible marijuana in Colorado. After eating a THC-infused candy bar, she wrote, “I lay curled up in a hallucinatory state for the next eight hours. I was thirsty but couldn’t move to get water. Or even turn off the lights. I was panting and paranoid, sure that when the room-service waiter knocked and I didn’t answer, he’d call the police and have me arrested for being unable to handle my candy.”

Tell Your Children: The Truth About Marijuana, Mental Illness, and Violence
by Alex Berenson
Free Press, 272 pp.

The column made Dowd the subject of national ridicule. A Vice headline blared, “Maureen Dowd Freaked Out on Weed Chocolate Because She’s Stupid.” By the time of her column, the idea that marijuana is a harmless recreational drug that has been unfairly targeted by hysterical drug warriors had become liberal gospel. But Dowd’s story might have raised a more troubling question: Can any drug that causes near-psychotic breaks, hallucinations, or pathological paranoia in a first-time user really be considered harmless? 

It’s a reasonable question that former New York Times reporter Alex Berenson attempts to answer in a new book, Tell Your Children. Berenson took a hard look at a vast body of scientific research on marijuana, and found that far from being a benign substance, it can cause profound damage to the brain, including psychosis and schizophrenia, and, with those things, violence. 

Berenson is an unlikely anti-drug warrior. For the past decade or so, he has devoted most of his time to writing a series of successful spy novels. Berenson tells us that he’d smoked weed a few times and never had particularly strong feelings about legalization one way or another. But one night a couple of years ago, he was talking to his wife, Jacqueline, about a case she’d been working on. A forensic psychologist, she evaluates mentally ill criminals for a living. She mentioned that the perpetrator of a particularly heinous crime—“somebody who’d cut up his grandmother or set fire to his apartment”—was high at the time, and a lifelong cannabis consumer, as were nearly all of her most deranged clients. Berenson was skeptical that marijuana had anything to do with mental illness, much less violent crime. Rather than argue the point, Jacqueline sent him to the scientific literature, a dive down the rabbit hole that resulted in this book. 

The title is subtly ironic: Tell Your Children is the original name of Reefer Madness, the 1936 campy cult film that was originally created as propaganda by a church group to educate parents about the dangers of marijuana. Marijuana legalization promoters in the 1970s repurposed the film as unintentional satire and used it as an example of the hysteria that had helped drive the nation’s overly punitive drug laws. But, as Berenson documents, the movie was based in part on reality.

The main psychoactive ingredient in cannabis, THC, has long been known to trigger paranoia and psychosis, which is often a precursor to full-blown schizophrenia. The first major study on the psychotic effects of marijuana was published in the Lancet in 1987 by Sven Andréasson, a doctor at the Karolinska Institute, the Swedish university that selects the recipient of the Nobel Prize in medicine. Andréasson dove into the subject in the early 1980s after he noticed that the schizophrenic patients who most often relapsed after being released from the hospital were the pot smokers. He wondered if the two things could be related. 

To find out, he plumbed a huge, robust data set covering 50,000 men born around 1951 who’d been conscripted into the Swedish military. Draftees, mostly eighteen- and nineteen-year-olds, were required to fill out comprehensive forms that included questions about their socioeconomic background, health, and drug use. Then, using national health service records, Andréasson was able to test whether men who’d used weed before 1970 had developed schizophrenia by 1983. 

The results, Berenson writes, were shocking even to Andréasson. After controlling for a host of factors and excluding anyone who was already suffering from schizophrenia at the time of conscription, Andréasson found that someone using cannabis on more than ten occasions had almost two and a half times the risk of developing schizophrenia than someone who’d never used it. To figure out if marijuana causes the disease or if people with schizophrenia just tend to self-medicate with it, Andréasson later compared people who developed schizophrenia after getting high to people with the mental illness who hadn’t used marijuana. The two groups turned out to be different: the pot smokers had been relatively normal and high-functioning before descending into psychosis, whereas the non-users had shown early signs of mental illness. Andréasson ultimately estimated that marijuana is likely responsible for between 10 and 15 percent of all psychosis cases.

The main psychoactive ingredient in cannabis, THC, has long been known to trigger paranoia and psychosis, which is often a precursor to full-blown schizophrenia.

Dozens of studies have subsequently made similar findings, including genetic research that’s made it possible to determine whether psychosis or marijuana use comes first. Having a parent or sibling with a serious mental illness increases the risk of cannabis-induced psychosis, but the drug use is also independently associated with psychosis in people with no family history of mental illness.

The potential dangers of marijuana seem most significant for young, developing brains. One study Berenson cites found that people who’d started using marijuana at age fifteen were four times more likely to develop schizophrenia and a related disorder than those who hadn’t. Even when researchers excluded kids who were showing signs of psychosis by the age of eleven, the risk was still three times higher. In the past year alone, both the American Medical Association’s Journal of Psychiatry and the British Journal of Psychiatry reported on new studies demonstrating strong links between teenage marijuana use and psychotic disorders. The evidence that marijuana can cause psychosis and schizophrenia is so strong that in 2017, the storied National Academies of Science, Engineering, and Medicine concluded that the issue was essentially settled, Berenson writes. (The organization also found very few medical benefits from cannabis, but reported that its use may worsen bipolar disorder and increase the risk of suicide and depression.)

NAM also found that the risk from marijuana is dose-responsive: the higher the use, the higher the risk. And what makes marijuana especially problematic is that doctors can’t predict which users might just end up mellow and fat, and which ones might jump off a hotel balcony in a psychotic rage, as nineteen-year-old first-time edible user Levy Thamba did in 2014. Potency is also an issue, argues Berenson. Today’s industrial-strength cannabis is far stronger than the stuff Brett Kavanaugh’s generation smoked in the 1980s. Edibles can contain as much as 100 milligrams of THC, about 100 times more than the average joint smoked in the 1980s.

Berenson seems on solid ground with the neuroscience of marijuana-induced psychosis. From there, he makes a far more controversial leap to arguing that marijuana also causes violent crime. The crux of Berenson’s argument goes like this: marijuana causes psychosis, and psychosis causes violent crime. Not everyone suffering from a psychotic episode simply curls up in a fetal position for eight hours until it’s over the way Maureen Dowd did. Paranoid, psychotic people commit a disproportionate number of violent crimes, and psychotic people who are also substance abusers commit even more violent crimes. 

Berenson describes observations of cannabis-related insanity and violence going back more than 100 years. Over the past decade, a host of new research has validated those observations, documenting a close relationship between marijuana and violence, often even when researchers hadn’t started out looking for it. Berenson says the connection between pot and violence is also showing up on the ground as the legalization movement has helped to nearly double the percentage of teens and adults who report using marijuana at least once a month since 2006. He argues that, far from living up to promoters’ promises of a lower crime rate, the first states to have fully legalized marijuana—Colorado, Washington, Oregon, and Alaska—are seeing sharp spikes in violent crime. “Combined, the four states saw a 35 percent increase in murders and a 25 percent increase in assaults between 2013 and 2017, far outpacing the national trend, even after adjusting for changes in population. (Across the United States, murders have risen 20 percent and aggravated assaults 10 percent over that period.)”

Untangling the reasons why crime rates rise and fall is notoriously tricky business, a problem Berenson acknowledges. And proving definitively that the recent murder increases have been caused by weed, legal or otherwise, is pretty much impossible, largely because the data just hasn’t been collected—an issue Berenson struggles with in the book. 

Indeed, after reading it, I thought I’d test Berenson’s theory to see whether Washington, D.C., where I live, has had an increase in pot-related crime. Marijuana was decriminalized here in 2014 and fully legalized by early 2015. The number of murders in the city is also way, way up. In 2013, the year before legalization, there were 104 homicides, including twelve from a single mass shooting at the Washington Navy Yard. In 2018, there were 155 by early December. 

There’s correlation, but is it causation? Drug-testing data, I thought, could shed a little light on that question, so I tried to look up how many people arrested in D.C. for violent crimes tested positive for cannabis. This turned out to be an unknowable number. As part of its decriminalization effort, the city’s pretrial services agency stopped testing criminal defendants for marijuana in 2012. 

The deep-pocketed legal weed industry—which now includes former Republican Speaker of the House John Boehner— will fight public health measures that might threaten profits. In that sense, it has the potential to become no different than the tobacco industry.

Such data deserts stymied Berenson, so the investigative reporter in him went at the problem in other ways. For instance, he requested autopsy reports of many of the thirty-five people who’d been killed in 2017 by police in Colorado. He got eighteen of the reports—all of which showed that the shooting subjects had drugs in their system. Cannabis was by far the most common drug. 

Drug use data also exists in many state child welfare systems, which provide some of the most disturbing numbers of the book. Berenson reports that in Texas in the 2017 fiscal year, the state recorded 172 deaths of children from abuse or neglect. In at least ninety of the cases, the people responsible tested positive for drugs, and by far the most common one was marijuana. Fifty-six of the perpetrators were actively using weed at the time of the child’s death, compared with twenty-three who were using alcohol. Berenson notes that the Texas figures are striking because marijuana use in the state isn’t especially high—he estimates that only about one in fifty adults uses it daily—yet more than a third of the perpetrators who killed a child through neglect or abuse were using weed at the time. 

Berenson finds a disturbing number of anecdotes to put faces on the numbers. This past August, for instance, a Texas man named Blair Ness allegedly stabbed his one-year-old son Ashton to death as horrified neighbors tried to stop him. “Neighbors told police Ness was yelling about Jesus; officers found his apartment reeking of marijuana,” Berenson writes. “Ness’s girlfriend told police that when she left for work a few hours before, he had been happily feeding the boy.” There’s also a pair of cases in late 2017 where young couples in Nevada and Idaho abused their small children to the point that they had seizures. The parents then blew marijuana smoke at the babies to try to stop the seizures. Both children died.

Tell Your Children is full of these sorts of horror stories—ax murders, matricide, corpse mutilation, and other heinous crimes committed by people while they were using weed. Horror stories don’t prove anything, of course. But the data Berenson musters and the science he cites provide a plausible biological explanation for the relationship between violence, psychosis, and marijuana. Tell Your Children thus makes a compelling case that weed legalization might deserve rethinking. 

Still, even Berenson doesn’t think marijuana should be re-criminalized, with small-time users sent to jail en masse. But he observes that there’s a big difference between decriminalizing possession and turning cannabis into a consumer product the way Colorado has. Making pot cheaper, more potent, and more available drives up use, and, with it, the drug’s negative effects. 

Berenson also challenges the idea that legal weed is a boon for public coffers. He points to Colorado, where in 2017 the state collected about $250 million in weed taxes, a tiny fraction of its $29 billion budget. Hospitalizing someone with psychosis for ten days costs more than $10,000. “It is possible that the costs of marijuana psychosis and violence alone already outweigh the taxes the industry pays in Colorado,” he writes.

Putting the brakes on the country’s move toward broader legalization of marijuana would be challenging. Even archconservative Mormon Utah recently passed a ballot measure legalizing medical marijuana, showing just how far public opinion has moved—though the state legislature is wisely replacing that measure with a version that imposes tighter regulations. A bigger obstacle is the formidable, deep-pocketed legal weed industry, which has a vested interest in promoting myths about the drug’s alleged crime reduction and health benefits. The industry’s lobbying and advertising forces—which now include former Republican Speaker of the House John Boehner, who recently joined the board of Acreage Holdings, a major investor in legal weed—will invariably work to muddy the science and fight public health measures that might threaten profits. In that sense, the marijuana industry has the potential to become no different than the tobacco industry. In fact, as I was writing this review, the tobacco giant Altria announced that it was spending $1.8 billion to acquire a controlling stake in Cronos Group, a cannabis company. 

More than anything, Berenson argues, policy needs to be driven by science, not industry pap. “Using cannabis or any drug is ultimately a personal choice. What to do about legalization is a political decision,” he writes. “But whether marijuana is dangerous to the brain and can ultimately cause violence is a scientific question, with a hard yes or no answer. We have that answer. It’s time you heard it.”

Stephanie Mencimer

Stephanie Mencimer is a senior reporter at Mother Jones and a Washington Monthly contributing editor.