Genetic Variation

Research suggests that genetic factors may predispose certain individuals, which explains why a family history of addiction leads to increased risk. Early life stressors, such as physical abuse, also seem to put people at more risk. When scientists look for "addiction genes," what they are really looking for are biological differences that may make someone more or less vulnerable to addiction. It may be harder for people with certain genes to quit once they start. Or they may experience more severe withdrawal symptoms if they try to quit. Factors that make it harder to become addicted also may be genetic. For example, someone may feel sick from a drug that makes other people feel good. But someone's genetic makeup will never doom them to inevitably become an addict.