Cannabis the evil weed?.

A comprehensive documentary looking at the pros and cons of cannabis use. The history of the cannabis plant is told and MRI scans of the brain show in which parts of the brain the cannabis receptors lie. Two regular users of cannabis for recreational purposes describe its effect on their lives. Steven Goldberg is experimenting with rats' tolerance levels to cannabis after a short period of use - in a further test he proves that rats exposed to cannabis have a higher tolerance for Heroin. Can cannabis lead to psychosis? Paul Floyd started smoking cannabis when he was 15 and had a schizophrenic breakdown - he and his family describe what happened. Cathy Fernandes studies long-term memory loss in mice who have been given cannabis, reaching the conclusion that drug use before the age of 18 can lead to long-term memory problems. Zerin Attakan has discovered that cannabis affects our ability to control impulses. Philip Robson from GW Pharmaceuticals is an expert in the therapeutic uses of cannabis and is trying to market the plant as a medication. He describes the different medical uses of two components of cannabis - THC and CBD.