marijuana

Dried leaves and flowers of the hemp plant cannabis, used as a drug; it is illegal in most countries. It is eaten or inhaled and causes euphoria, distortion of time, and heightened sensations of sight and sound. Mexico is the world's largest producer.

A report released in March 1999 by the Institute of Medicine in the USA said that marijuana should have clinical tests because it helps fight pain and nausea. However, in May 2001, the US Supreme Court ruled that patients may not use marijuana to relieve pain, and the drug could not be sold for medical purposes.

A US study involving 3,882 people who had survived heart attacks revealed that smoking marijuana may increase the risk of a heart attack, by as much as five times for an hour after smoking. The risk may increase because marijuana increases the heart rate by about 40 beats a minute.