Definition:
Addiction is a complex condition, a brain disease, that is manifested by compulsive subtance use despite harmful consequence. People with addiction (severe substance use disorder) have an intense focus on using a certain substances, such as alcohol or drugs, to the point that it takes over their life. They keep using alcohol or a drug even when they know it will cause problems.
Despite all of this, effective treatments are available, people can recover from addiction, and lead normal, productive lives.