Gateway drug theory
（重定向自Stepping stone theory）
![Cannabis](/Images/godic/202502/13/Cannabis_leaf.svg0436.png")
The gateway drug theory (also called gateway theory, gateway hypothesis and gateway effect) states that use of less deleterious drugs precedes, and can lead to, future use of more dangerous hard drugs or crime. It is often attributed to the earlier use of one of several licit substances, including tobacco or alcohol, as well as cannabis.