The twentieth century saw a remarkable upsurge of research on drugs, with major advances in the treatment of bacterial and viral infections, heart disease, stomach ulcers, cancer, and mental illnesses. These, along with the introduction of the oral contraceptive, have altered all of our lives. There has also been an increase in the recreational use and abuse of drugs in the Western world. This Very Short Introduction, in its second edition, gives a non-technical account of how drugs work in the body. Reviewing both legal (alcohol, nicotine, and caffeine) and illegal drugs, Les Iversen discusses why some are addictive, and whether drug laws need reform. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.