Survey respondents believe drug can alleviate various ailments, even as scientists call out for more research

This article is more than 2 years old

This article is more than 2 years old

Americans believe marijuana is helpful in treating a variety of health problems despite a lack of available evidence supporting it, a new survey found.



The results, to be published in the upcoming issue of the Annals of Internal Medicine, show the most respondents believe smoking marijuana can help with pain management and then MS. Just under half believe it can relieve insomnia, anxiety and depression, ailments for which marijuana’s efficacy and safety have not been established by scientists.

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“They believe things that we have no data for,” said the study’s lead author, Dr Salomeh Keyhani, a professor of general internal medicine at the University of California San Francisco medical school.

Of the 16,000 respondents to the online survey, 14.6% said they had used marijuana in the past year, lower than in the country at large, according to a 2017 survey.

In the US, marijuana’s unique legal situation complicates efforts to study and obtain accurate information about the drug’s harms and benefits.

According to the US Drug Enforcement Administration, the agency responsible for drug law enforcement, marijuana is a schedule I drug, meaning that it has serious risks and no medical benefits. Other drugs in this category include heroin and LSD.

This restricted status makes it difficult for scientists to study marijuana, especially its health benefits.

“We need better data,” Keyhani said. “We need any data.”

She attributes the gaps between public perception and proven science largely to commercialization of the drug in several US states, which has led to advertising and media coverage.

Facebook Twitter Pinterest Thirty-one US states have legalized cannabis for medical use. Photograph: Gareth Fuller/PA

To pro-cannabis activists, the lack of traditional research lends credibility to anecdotal evidence, or allows them to point to research on animals or from pre-clinical lab studies not normally used to demonstrated a substance’s medical benefits for humans.



At the same time, marijuana’s schedule I status has lost credibility in recent years. In June, the US Food and Drug Administration (FDA) approved Epidiolex, a first for a drug derived from the marijuana plant. The drug, developed by the UK firm GW Pharmaceuticals, won approval to treat certain severe pediatric epilepsy disorders.

In addition, 31 US states have legalized medical marijuana for a wide variety of illnesses, such as post-traumatic stress disorder, for which there is not medical proof of efficacy. To alleviate the current opioids crisis some states, including New York, are willing to allow anyone prescribed an opioid wide latitude to replace it with medical marijuana.

Respondents believe things that we have no data for Salomeh Keyhani, lead author

The survey also found 18% of US adults believe smoking marijuana is somewhat or completely safe for adults. A smaller segment of the population, 7.3% believe it is somewhat or completely safe for children to be exposed to secondhand pot smoke and that marijuana use is safe during pregnancy. These beliefs do not have a basis in mainstream science.



The most common dangers respondents associated with marijuana use were legal problems, addiction and impaired memory.

A recent study in the Lancet found marijuana does not reduce chronic pain or help replace opioids.



However, a different recent study published in the journal Addiction found an association between states which have legalized medical marijuana and a reduction in prescriptions for schedule III opioids. It did not find evidence of drops in prescriptions for more powerful schedule II opioids.

Mixed signals regarding marijuana’s potential dangers and benefits have enabled the commercial marijuana industry to promote a maximalist view of marijuana’s possible benefits. Since direct unproven claims of marijuana’s medical benefits, and assertions such as that a product cures cancer, can lead to unwanted attention from the FDA regulators, cannabis companies have learned to be much more subtle.

Starting with the largely uncontested assertion that no one has ever died from a marijuana overdose, companies will often go on to promote softer, if still unproven, notions of cannabis’s curative properties. For example, the website of the California company Papa & Barkley features testimonials from customers who say the company’s products relieved their arthritis pain, anxiety, insomnia and a guitarist’s finger cramps.