In the U.S.A the Harrison Narcotics Tax Act was passed in 1914 to control the sale and distribution of heroin and other opiates. The law did allow heroin to be prescribed and sold for medical purposes. In particular, recreational users could often still be legally supplied with heroin and use it. In 1924, the United States Congress passed additional legislation banning the sale, importation or manufacture of heroin in the United States. It is now a Schedule I substance, and is thus illegal in the United States. Short-term effects of marijuana use include memory loss, distorted perception, trouble with thinking and problem solving, and anxiety. Students who use marijuana may find it hard to learn, thus jeopardizing their ability to achieve their full potential. In 1988, about 300,000 infants were born addicted to cocaine. Although the root causes of drug addiction remain unclear, the new study reveals that scientists have identified a number of biological, psychological and social conditions that can help to identify whether a person will become an addict. | 
