Substance Abuse refers to the use of a substance in a way that is not in accordance with medical or social norms, or that results in negative consequences. This can include using drugs, alcohol, or other substances in excessive or harmful amounts, or using them in a way that interferes with daily life, such as missing work or school, neglecting responsibilities, or engaging in risky behaviors. Substance abuse can be a precursor to addiction if it continues over time.

Addiction, on the other hand, is a chronic and complex condition that is characterized by compulsive drug or alcohol use, despite the negative consequences it has on an individual's physical, mental, social or financial health.

In summary, substance abuse is characterized by misuse of drugs or alcohol, while addiction involves compulsive use of drugs or alcohol despite negative consequences and a change in the individual's brain circuitry. Substance abuse can lead to addiction if continued over time.