Definition
Substance abuse refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. It involves using these substances in a way that causes problems for the individual or others. Unlike responsible use, substance abuse leads to negative consequences. Think of it as overusing a medicine, even when you know it's harmful. It's more serious than occasional use; it's a pattern of harmful behavior. It is the opposite of moderation and healthy habits.