Summary: Tell Your Children

The GIST

Tell Your Children by Alex Berenson is a deliberately provocative warning shot fired at the idea that marijuana is harmless. Published in January 2019 with the subtitle "The Truth About Marijuana, Mental Illness, and Violence," it argues that legalization has run far ahead of the science. Berenson, a former New York Times reporter and award-winning spy novelist, compresses his case into three short sentences: "Marijuana causes psychosis. Psychosis causes violence. The obvious implication is that marijuana causes violence." He calls the book a "bullhorn" for scientists and physicians whose findings, he believes, have been drowned out by the marijuana lobby.

It matters because it landed in the middle of a rush toward legal cannabis and forced an uncomfortable conversation. It is also one of the most disputed books of its kind. Malcolm Gladwell, writing in The New Yorker, praised Berenson's "reporter's tenacity" and "novelist's imagination," while many scientists and doctors denounced the book as alarmist and accused it of confusing correlation with causation. This is an advocacy book, not a neutral review, and it is best read knowing both what it claims and where the experts push back.

The Big Ideas

A Skeptic Changes His Mind

Berenson begins by admitting that he once thought the way most of his readers do. He has smoked marijuana himself. He expects many people to find his argument silly and to be reminded of the "ridiculous" 1936 film "Reefer Madness," and he imagines them objecting that this is propaganda and that the drug is safe, far safer than alcohol.

What changed his mind was a conversation at home. His wife, Jacqueline, is a forensic psychiatrist, trained at Harvard and Columbia, whose job is to evaluate mentally ill people who have committed crimes. Describing one horrific case, the sort where someone had "cut up his grandmother or set fire to his apartment," she remarked, almost as a matter of course, that the man had been high and had smoked pot his whole life. Nearly all her patients, she told him, had used marijuana heavily, many of them at the time of their crimes. Berenson did not believe her. She told him to go and read the evidence himself, and the more he read, the more he decided she was right.

He is frank that he is "not a scientist or physician." His claim to the subject is that he spent years covering the prescription drug industry for The New York Times, and knows how to read studies and question the people who write them.

The book itself opens in a courtroom in Queensland, Australia, where a Supreme Court judge ruled that a woman who had committed a terrible act of violence had paranoid schizophrenia and could not have known that what she did was wrong. The judge noted that she had used cannabis since the ninth grade and that psychiatrists believed this long use had probably brought her illness on. Berenson presents it as one of the first judicial findings anywhere to tie together marijuana, schizophrenia and violence, and it sets the pattern for everything that follows.

An Old Suspicion: Cannabis and Madness

The idea that cannabis can unhinge the mind, Berenson shows, is anything but new. He goes back to the first published reports of marijuana-related psychosis, which came from British India and from Mexico in the early twentieth century. He then follows the changing understanding of schizophrenia across some two hundred years, as medicine slowly learned to describe and diagnose the illness.

The purpose of this history is to turn the usual story around. In the common telling, fears about cannabis were invented by moralists and then debunked. In Berenson's telling, careful observers in very different times and places kept noticing the same thing, and it was the later culture that chose to forget. Even so, he grants that a great deal more research on cannabis and mental illness is still needed.

The Science of Psychosis

This is the core of the book. Berenson argues that THC, the chemical in cannabis that produces the high, can cause psychosis, a break with reality marked by paranoia and delusions, and can bring on schizophrenia in some users. He concedes that no single study proves this. His case is that several separate lines of evidence, from large population studies and from the laboratory, all point in the same direction.

Much of that evidence comes from Britain. Because the country can track drug use and mental health outcomes over long periods, British researchers spotted the connection decades ago, and Berenson travels to the London institute whose scientists did much of the work. He stresses that the risk rises with the dose: the more someone uses, the greater the danger. He also leans on a major 2017 report on cannabis from the National Academies of Sciences, Engineering, and Medicine, and adds an analysis of his own, carried out with Sanford Gordon, a politics professor at NYU, which found that looser marijuana laws were followed by more emergency room visits by patients diagnosed with both psychosis and marijuana use disorder. By his account, scientists "no longer seriously debate" whether marijuana causes psychosis.

Here the critics object most sharply. Ziva Cooper, a member of the National Academies committee, said Berenson had misread its report: the committee found an association between cannabis and schizophrenia, but not enough evidence to say that one causes the other. "To say that we concluded cannabis causes schizophrenia, it's just wrong," she said. The fair middle ground is that a link between heavy, early use of strong cannabis and psychosis is widely accepted. Whether cannabis clearly causes schizophrenia is exactly what remains in dispute. Gladwell made a similar point about how little is settled: "we really don't know very much."

From Psychosis to Violence

The second step of Berenson's argument is that psychosis raises the risk of violence, and so cannabis must too. He builds it first from cases, told with a thriller writer's eye: killings, courtrooms and prison interviews. His signature example is a Colorado man serving thirty years after eating a THC-laced candy bar and killing his wife.

Then he turns to numbers. Berenson reports that murders in the four states that legalized first, Washington, Colorado, Alaska and Oregon, rose 25 percent after legalization, more than the national increase, and that statistical analysis shows the rises in murder and aggravated assault were unlikely to be chance. He adds that in Uruguay, which began retail sales in 2017, murders "soared." Cannabis-linked violence, he warns, is spreading.

These are his figures and his reading of them, and this is where even friendly reviewers hesitated. The Drug Free America Foundation, an anti-legalization group that liked the book, called the state-level argument its "weakest link." Others pointed to research finding that marijuana use does not induce violent crime, and one researcher compared the reasoning to claiming that organic food causes autism because both have risen together. Berenson has not backed down. Correlation, he has told audiences, is evidence of causation.

The Myths of Legalization

Having made his case about harm, Berenson turns on the arguments for legalization, which he says rest on myths.

The first is that marijuana arrests fill the prisons. "Almost no one is in prison for marijuana," he writes. The second is medical marijuana. He argues that a tiny fraction of doctors write most of the authorizations, mostly for people who were already users, and that medical legalization is, in his words, "simply a backdoor way to protect recreational users from arrest." The result, he believes, has been to confuse the public about the drug's real risks and benefits. Critics answer that he leaves out studies finding cannabis useful for conditions such as chronic pain.

The third is that cannabis can help end the opioid epidemic. Berenson argues the opposite: use of marijuana, opiates and cocaine tends to rise and fall together. Since 2008, he notes, the United States and Canada have seen both soaring marijuana use and an opiate crisis, while Britain has seen falling use and no such epidemic. This gateway argument drew more scorn from critics than any other part of the book.

Behind all of it he sees money: an industry with every reason to play down what its product can do. But he is not blind to the other side. He interviews leading advocates of nationwide legalization, and says of one, "I liked him. He's not trying to get rich off legalization. And his concerns are impossible to discount." He even allows that racial disparities in marijuana arrests might be so overwhelming "that every other factor pales."

In the epilogue he states his own position plainly: he opposes legalization. He asks readers to take seriously the risks to mental health and public safety, calls for much more long-term research, and urges caution in the meantime.

Putting It to Work

• Take THC seriously as a mental-health risk. Whatever one makes of Berenson's larger claims, the concern is strongest for teenagers and for heavy users of high-potency products. The title is an instruction: this is a warning for parents to pass on.
• Remember that dose matters. In the research Berenson cites, risk climbs with how much and how often someone uses.
• Question the word "medicine." Berenson urges skepticism toward the idea that most cannabis use is medical, and wants readers to ask what the evidence for a given benefit actually is.
• Ask lawmakers to slow down. His policy message is that legalization should wait for the science to catch up.
• Read it alongside its critics. Berenson says he expected a serious backlash and chose to "lean in." Readers should lean in too: weigh his cases and numbers against the objections that association is not proof, and note that some readers complained the book prints no bibliography.

Who Should Read It

Parents of teenagers, lawmakers and voters weighing legalization, and anyone who suspects the cheerful consensus about "harmless weed" is a little too rosy. It reads quickly, with the pace of a thriller, and it will sharpen your thinking even where you end up disagreeing. Readers who want a balanced scientific review should pair it with the critical responses, because this is one side of an argument, made as forcefully as its author knows how.

This has been a summary of Tell Your Children by Alex Berenson, giving you the GIST so you can decide if you want the REST.