What is Addiction?

Addictive substances like alcohol and drugs cause the brain to release high levels of chemicals that are associated with pleasure or reward. Over time, the continued release of these chemicals causes changes in the brain systems involved in reward, motivation and memory. Because of this, a person may need the substance to feel normal. These changes in the brain can remain for a long time, even after the person stops using the substance and leave the individual vulnerable to an increased risk of relapse.