Legalizing Marijuana Isn't Risk-Free

While pot does have some proven medical benefits, especially when it comes to pain, legalization may have some unintended negative consequences.

by Lara DeSanto Health Writer

While legal marijuana has been found to have the major, important benefit of reducing chronic pain, legalization of the drug in Colorado may have resulted in some other not-so-great changes: an increase in marijuana abuse, alcohol abuse, overdose, and car accidents.

In a review of nearly 30 million hospital records from two years before and after Colorado made pot legal, researchers at UC San Francisco (UCSF) found that diagnoses of chronic pain dropped 5% after legalization. But they also found that hospitalizations for cannabis abuse increased compared with other states; car accidents rose 10%; alcohol abuse and drug overdose that resulted in injury or death increased 5%, according to the study published in the journal BMJ Open.

The overall number of hospital stays didn’t change much after weed was legalized, researchers found—perhaps because the positive and negative effects (including those still unknown) balanced each other out.

"We need to think carefully about the potential health effects of substantially enhancing the accessibility of cannabis, as has been done now in the majority of states," said senior study author Gregory Marcus, M.D., a UCSF Health cardiologist and associate chief of cardiology for research at the university. "Our findings demonstrate several potential harmful effects that are relevant for physicians and policymakers, as well as for individuals considering cannabis use."

There are “good” and “bad” effects of legalizing recreational cannabis, but it’s important to keep in mind that the effects likely depend on each person’s needs and circumstances, researchers said.

“Using revenues from recreational cannabis to support this sort of research likely would be a wise investment, both financially and for overall public health,” said Dr. Marcus.

Marijuana for Chronic Pain: Things to Know

The positive part of this—that chronic pain-related hospitalizations are down—is great news for people with painful chronic conditions and aligns with the 2017 report from the National Academy of Sciences that conclude there is plenty of evidence that weed does effectively reduce chronic pain. Cannabis contains chemicals called cannabinoids, including THC and CBD, that work in different ways in the body to relieve pain.

The legalization of pot makes it easier for people with chronic pain conditions to get that relief when traditional treatments aren’t enough. For example, some people with different forms of arthritis find that cannabis works wonders for their pain and doesn’t have the sometimes-nasty side effects of other drugs used to treat their pain.
While it’s still illegal in the eyes of federal law to use marijuana, 28 states and Washington, D.C., have legalized medical marijuana, and nine of those have legalized it for recreational use—including Colorado.

So if you want to get your hands on some pot to try reducing your pain, where do you start? It’s always wise to first speak with your primary care physician about your options, along with the risks and benefits for your specific situation. And depending on the state you live in, your condition may or may not qualify for treatment with medical marijuana.

To get medical marijuana from a dispensary, you need a formal recommendation from a doctor, according to Practical Pain Management. Check out their 10 tips for getting and using cannabis for chronic pain here. And remember: You should always make sure you’re buying your cannabis from a qualified dispensary, too.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at