Research shows that about 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6.

The words cannabis, marijuana, hemp, and hash are interchangeable terms used when referring to the controversial plant.

A recent study conducted at Duke University, New Zealand, has proved that those who started heavily smoking marijuana as teenagers and developed an addiction lost an average of eight IQ points.