April 20 (or 4/20 as many refer to it as) is a celebratory date for marijuana enthusiasts throughout the world. It’s a date recognized in the cannabis subculture for gleefully smoking a joint or participating in any other related activity.

Many public figures have celebrated marijuana. But as more research becomes available, science shows it may not be the whimsical herb many claim it to be. There are many significant negative consequences to using marijuana, including links to mental illness, extreme violence, and mass murder.