Marijuana has been used by people for many centuries for medical purposes. It is a natural pain reliever used today as a recreational drug by people all over the world. According to Noel Merino in “Introduction to Gateway Drugs: Opposing Views,” “a drug is something other than food intended to affect the structure or function of the body.” Marijuana is a very controversial drug and has been outlawed in many countries due to its effects on body functions. “Effects may involve hallucinations, impaired judgment and mood swings.” Describes the effects of marijuana in the Macmillian social science library “Marijuana” Current Issues. Over the last century marijuana has been legal, made illegal, strictly enforced, decriminalized, protested, used illegally by millions, protested on both counts, legalized for medical uses, and the debate continues. People argue that marijuana is not harmful and should be made legal; others protest that it is a dangerous drug that leads to other serious personal, social and political problems. Marijuana can cause physical effects such as breathing problems due to smoke inhalation if this is the method used to take the drug. In “Marijuana is Dangerous for Teens,” by Joseph Califano, it is stated that “9% of those who use marijuana become addicted to it,” although it is not a large number it is because this is not the biggest problem of marijuana. Along with all the health problems caused by marijuana use comes the debate over the front door theory. A gateway drug is a substance taken that opens people's minds to taking other, progressively more dangerous drugs. Millions of people who use marijuana use it illegally at some point but...... middle of paper...... Sun-Times, December 24, 2006 Andrew Morral, Daniel McCaffrey and Susan Paddock, “Reassessing the Marijuana Gateway Effect” Addiction, vol. 97, December 2002, pp. 1493-1504. Society for the Study of Addiction to Alcohol and other Drugs “Introduction to Gateway Drugs: Opposing Views.” Gateway drugs. Ed. Noël Merino. Detroit: Greenhaven Press, 2008.Califano, Joseph A., Jr. “Marijuana Is a Dangerous Drug for Teens.” Marijuana. Ed. Mary E. Williams. San Diego: Greenhaven Press, 2003.Joseph C. Gfoerer, Li-Tzy Wu, and Michael A. Penne, Initiation of Marijuana Use: Trends, Patterns, and Implications, Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2002. “Marijuana.” Current Issues: Macmillian Library of Social Sciences. Detroit: Gale 2010. Gale Opposing Views in Context. Network. 9 June 2011