A lawsuit filed in federal court in Illinois against cannabis dispensaries alleges that consumers were not adequately warned about potential mental health risks of marijuana use, including psychosis and schizophrenia among vulnerable individuals. Predictably, critics of cannabis legalization are already using the lawsuit to argue that lawmakers should mandate stricter warning-label requirements and enact broader regulation of legal cannabis markets.

That conclusion does not follow.

Adults deserve truthful information about the products they consume. Cannabis is no exception. Heavy cannabis use — particularly among adolescents, frequent users and people with certain psychiatric vulnerabilities — is associated with elevated risks of anxiety, paranoia, psychotic episodes and other mental health problems. Consumers should receive clear and accurate information about those potential harms.

But there is an important difference between information that evolves through legal accountability and information imposed through politicized bureaucratic mandates.

If dispensaries or manufacturers make unsupported medical claims, conceal known risks or fail to disclose foreseeable dangers, consumers should have legal recourse. Civil liability and tort law can encourage warnings and disclosures to evolve organically as evidence emerges.

That process is imperfect, but it is also flexible. It allows standards to adapt to new information rather than locking them into bureaucratic mandates that often outlast the science behind them.

Sweeping warning-label mandates imposed by federal agencies or state public health bureaucracies often become rigid, one-size-fits-all and detached from evolving evidence. They are also vulnerable to political and special-interest pleading. 

More importantly, once government agencies acquire authority over what adults may hear, buy or consume “for their own good,” the temptation to shift from informing consumers to restricting them becomes hard to resist.

We have seen this pattern repeatedly in drug policy.

Cannabis itself was prohibited for decades amid exaggerated claims untethered from serious scientific analysis. More recently, public health authorities often presented opioids in starkly moralistic terms that blurred the distinction between medical use, misuse, dependence and addiction. The result was not better-informed patients, but rather a climate of fear that transformed the doctor-patient relationship and left many legitimate pain patients stigmatized, undertreated or abandoned.

Adults should retain the freedom to make choices, even when those choices involve risk.

Risks associated with cannabis are already being cited by some commentators as evidence that legalizing it was a mistake. But the mere existence of risk has never been sufficient reason to abandon adult choice. Alcohol carries well-established dangers involving liver disease, violence, accidents and mental health harms. Yet we do not conclude that adults must therefore be prohibited from drinking. Psychiatric medications carry black-box warnings for suicidality in younger patients, dependency risks and difficult withdrawal syndromes. Yet we still allow adults, in consultation with physicians, to decide whether the benefits outweigh the harms.

Cannabis should be treated similarly.

Consumers deserve honest information, not propaganda from either side. They should not be told cannabis is harmless, nor should they be subjected to a new generation of “reefer madness” exaggerations dressed up as public health concern.

There is also reason for caution when interpreting claims about causation. Associations between cannabis use and mental illness are real, but they are often complex. Many studies show correlations, particularly among heavy users and those predisposed to psychiatric illness. That is not the same thing as proving cannabis directly causes schizophrenia or other psychiatric disorders in otherwise healthy individuals.

Investigators also face a persistent “chicken or egg” problem. People experiencing early symptoms of anxiety, depression, trauma or psychosis may turn to cannabis in an attempt to self-medicate distress long before receiving a formal diagnosis. That makes it difficult in many cases to determine whether cannabis precipitated the illness, worsened an underlying vulnerability or was simply used by people already struggling with emerging psychiatric conditions.

That uncertainty is precisely why caution is warranted before converting evolving scientific associations into rigid narratives or one-size-fits-all warning mandates.

A free society does not require the government to sanitize life of risk. It requires truthful information, personal responsibility and legal accountability for fraud or concealment.

If the Illinois lawsuit prompts cannabis companies to provide clearer and more honest information about potential risks, that may ultimately benefit consumers. But if it becomes another vehicle for moral panic, exaggerated claims or backdoor prohibitionism, it will repeat mistakes the country has already made too many times before. 

Dr. Jeffrey A. Singer practices general surgery in Phoenix and is a senior fellow at the Cato Institute. His book is “Your Body, Your Health Care.”

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