Substance abuse and substance dependence are related terms but have distinct definitions.
Substance abuse refers to the use of a substance in a way that is harmful or hazardous to an individual’s health or well-being, or to the well-being of others around them. This can include using a substance in larger amounts or for longer periods of time than intended, or using a substance despite knowing that it is causing problems in one’s life.
Substance dependence, on the other hand, is characterized by a strong physical and/or psychological reliance on a substance. An individual with substance dependence may experience withdrawal symptoms when they attempt to stop using the substance, and they may continue to use the substance despite negative consequences.
In short, substance abuse refers to harmful use of a substance, while substance dependence refers to a more severe form of substance use disorder characterized by physical and/or psychological dependence on the substance.