Substance abuse and addiction occur when the use of drugs or alcohol begins to negatively impact a person’s health, behavior, relationships, or ability to function, often progressing from coping or social use into dependence. Addiction is not a moral failure or lack of willpower, but a chronic brain condition that affects decision-making, emotional regulation, and impulse control, making it difficult to stop even when consequences are serious. Codependency commonly develops alongside addiction, especially in close relationships, when one person becomes overly focused on managing, fixing, or protecting the person using substances, often sacrificing their own needs and unintentionally enabling the addiction by removing natural consequences.