Substance use disorders include substance abuse and substance dependence. If you have a substance use disorder, it does not mean you are addicted to drugs or alcohol. A substance use disorder happens when you use a substance, such as tobacco, alcohol or drugs too often. This may lead to health issues, missing work and school, or problems in your relationships. You are more likely to suffer from a substance use disorder is your parents abused substances when you were a child. This is due to both a genetic and environmental connection that you have with substance use. Prevention and early inter