Which is worse for you: weed or whiskey?
It's a tough call, but based on the science, there appears to be a clear answer.
Keep in mind that there are dozens of factors to account for, including how the substances affect your heart, brain, and behavior, and how likely you are to get hooked.
Time is important, too — while some effects are noticeable immediately, others only begin to crop up after months or years of use.
The comparison is slightly unfair for another reason: While scientists have been researching the effects of alcohol for decades, the science of cannabis is a lot murkier because of its mostly illegal status.
More than 30,700 Americans died from alcohol-induced causes in 2014. There have been zero documented deaths from marijuana use alone.
In 2014, 30,722 people died from alcohol-induced causes in the US — and that does not count drinking-related accidents or homicides. If those deaths were included, the number would be closer to 90,000, according to the Centers for Disease Control and Prevention.
Meanwhile, no deaths from marijuana overdoses have been reported, according to the Drug Enforcement Administration. A 16-year study of more than 65,000 Americans, published in the American Journal of Public Health, found that healthy marijuana users were not more likely to die earlier than healthy people who did not use cannabis.
Marijuana appears to be significantly less addictive than alcohol.
Close to half of all adults have tried marijuana at least once, making it one of the most widely used illegal drugs — yet research suggests that a relatively small percentage of people become addicted.
For a 1994 survey, epidemiologists at the National Institute on Drug Abuse asked more than 8,000 people from ages 15 to 64 about their drug use. Of those who had tried marijuana at least once, roughly 9% eventually fit a diagnosis of addiction. For alcohol, the figure was about 15%. To put that in perspective, the addiction rate for cocaine was 17%, while heroin was 23% and nicotine was 32%.