In less than 25 years, marijuana has gone from illegal everywhere in the United States to legal for at least some uses in all but four states.
Advocates say the drug can help patients who are suffering from chronic pain, multiple sclerosis-triggered muscle spasms and the grueling side effects of chemotherapy. Some states are exploring whether cannabis could help wean people from addiction to opioids.
Beyond the medical claims, 10 states and the District of Columbia have legalized marijuana for recreational use, and more are considering it. The advocates’ long-repeated argument: It’s safer than alcohol or tobacco.
But as cultural acceptance of cannabis grows, opponents are warning of potential downsides.
These critics – doctors, police and auto safety officials, parents – point to stories and studies that link the drug to suicide, schizophrenia and car crashes.
Marijuana might be safer than alcohol or tobacco, they say. But that doesn’t make marijuana safe.
An increase in impaired driving by people under the influence of drugs including marijuana, for example, is threatening the huge progress made in recent decades to reduce drunk driving crashes.
Car crashes rose 6 percent from 2012 to 2017 in four states that legalized marijuana – Nevada, Colorado, Washington and Oregon – more than four comparable states that didn’t, the Highway Loss Data Institute found.
Matt Moore is senior vice president at the institute, which is funded by the insurance industry.
“It makes me very nervous about highway safety as many more are considering legalizing it for recreational use,” he says.
Some in medicine warn of possible links between marijuana and psychosis. They say more study is needed.