Caffeine is one of the most heavily produced, distributed, and used drugs in the world. It is common not only in many food products but also in many medicines. Caffeine is often used for its many emotional and physical health benefits, but overuse can cause negative mental and physical health effects. Caffeine is one of ten titles in the Young Adult Drug Library series. Nine titles spotlight a major drug or type of drug (such as painkillers); discuss the negative physical and mental effects of the addiction on the addict and the potential benefits of their use (for certain legal drugs); and provide an overview of treatment strategies for the addiction. The last title, Facts & Figures, provides readers with the "big picture" regarding drugs, including their pros and cons; how they are made, distributed, sold, and used; why they are abused or misused; and treatment options for those who become addicted. Stories of those who are battling drug addiction are also featured in the series in order to humanize these issues.