The cannabis plant is used globally for the changes it causes in our perception, and is the most commonly used recreational drug in the world. How can cannabis impact our brains? What neurological mechanisms are invovled? Why do we get high? In this film, developments in the cannabis research and its future medical applications are surveyed by Prof. Raphael Mechoulam. Prof. Mechoulam and colleagues, from The School of Pharmacy of The Faculty of Medicine at The Hebrew University of Jerusalem, discovered in 1964 the main active compound in cannabis, Δ9-tetrahydrocannabinol, better known as THC. This film was produced by the Chief Scientist Office of the Israeli Ministry of Health in the framework of ERA-NET NEURON, a pan European organization which receives funding under the Sixth Research Framework Programme (FP6) of the European Union. It is provided as a service to the public. Find out more at: http://www.neuron-eranet.eu