Absolutely. All diseases have some heritable component (this means that you can inherit them), but how much can vary. Here's an example. Huntington's disease is caused by a genetic defect that, if passed on, causes a person's offspring (their child) to be affected. That means that Huntington's is 100 percent genetic. Inheritance, in the form of genes, plays a large role in drug addiction also. BUT while genes play a big role, they are only part of the picture. Other factors, like having friends who don't use drugs, or being involved in sports and other recreational activities, also affect your risk of trying drugs and of becoming addicted to them. Researchers are trying to find the genes that make you vulnerable or resistant to addiction, in order to find ways to improve treatment and prevention approaches. Want more information on genes, addiction and teens? Check out NIDA's website, http://www.teens.drugabuse.gov/