People use drugs for many reasons. One of the reasons that heroin is so widely used, especially in teenagers, is because it is a cheaper drug and one that is usually easy to get.
Many people, especially teenagers, use drugs because of peer pressure. They may have friends that do it so they do it too in order to try to fit in. Heroin is very addicting so once it is used once it is incredibly tempting to do it again.
Another resaon that people may use heroin, or other drugs, is because of depression. Drugs are often used as a way to escape the harsh realties of life that one may be encountering.