Add Your Name: Scholars & Clinicians Oppose Junk Science about Marijuana

In a book released last week, reporter and novelist Alex Berenson attempts to stir up public fear over marijuana legalization.This sort of alarmism has been around since the earliest days of prohibition. Rather than contributing to thoughtful debate, his work is a polemic based on a deeply inaccurate misreading of science.
We, as scholars and clinicians, want to highlight and refute some of the specious arguments in Tell Your Children and reiterate our support for an end to marijuana prohibition and for the legal regulation of marijuana for adult use.
Overview of the Problems with the Scientific Claims of the Book:
Attributing cause to mere associations. Berenson irresponsibly and dangerously claims a causal link between marijuana use and increases in rates of psychosis and schizophrenia, which have purportedly led to increases in population-level violence. While associations between marijuana use and mental illness have been established, research suggests that the association is complex and mediated by multiple factors other than marijuana, including genetics. Similarly, associations between individual characteristics and violence are multi-factorial. Thus, establishing marijuana as a causal link to violence at the individual level is both theoretically and empirically problematic. Further weakening his arguments, the vast majority of people who use marijuana do not develop psychosis or schizophrenia, nor do they engage in violence, thus making Berenson’s claims far-reaching and exaggerated.
Berenson cherry-picks data. He misunderstands and incorrectly contextualizes homicide data and its (non-existent) link to marijuana legalization. Quite simply, there is no proof, reasonable or otherwise that meets the criteria needed to scientifically link the legalization of marijuana to increases in homicide at the state level. For a more reliable examination of the relationship between marijuana use and homicide, please see The Incidental Economist here
Berenson is guilty of selection bias. When he looks to anecdotes provided by his wife, a forensic psychiatrist, he has pre-selected a population that is skewed toward exhibiting the sorts of symptoms and behaviors seen by forensic psychiatrists. These are not random effects and should not elicit warnings and fearmongering directed at the general population.
In addition to his flawed use of science, Berenson’s argument outright ignores most of the harms of prohibition, focusing narrowly on the harms of marijuana use. None would argue that marijuana use is risk-free. However, weighed against the harms of prohibition, including the criminalization of millions of people, overwhelmingly Black and Brown, and the devastating collateral consequences of criminal justice system involvement, legalization is the less harmful approach.
It should be clear that the harms Berenson raises are unlikely to be ameliorated by his proposed “compromise” solution - decriminalization. Decriminalization preserves many of prohibition’s troubling harms, such as the violence associated with drug sales and trafficking, racially-biased enforcement, and lack of information about the quality and content of marijuana and marijuana products.
Hardly harmless. In one of his book’s most disturbing passages, Berenson suggests that one of the reasons that police so disproportionately arrest black people (three times as often as whites) for marijuana use is that marijuana makes young black people mentally ill and violent.
He writes,
Yes, marijuana arrests disproportionately fall on minorities, especially the black community. 
But marijuana’s harms also disproportionately fall on the black community.....
Given marijuana’s connection with mental illness and violence, it is reasonable to wonder whether the drug is partly responsible for those differentials.
Conveniently, Berenson ignores the fact that black and white people use marijuana at the same rates and that the reason for the higher rate of arrests is over-policing of communities of color, based on prohibition. Berenson’s irresponsible and inaccurate statement reeks of the crack baby and super-predator myths of the 90s. And though the scientific evidence clearly refutes both theories, we are still working to roll back draconian policies based on those myths today. Tell Your Children race-baits with its pictures of Black marijuana-fueled aggressors, while simultaneously perpetuating uninformed stigma about schizophrenia.
When research is misrepresented to uphold and perpetuate the worst myths about people of color and people with mental illness, we are required to speak up
We urge policymakers and the public to rely on scientific evidence, not flawed pop science and idelogical polemics, in formulating their opinions about marijuana legalization.