A compulsive or uncontrollable engagement with substances or behaviors that make the person feel good A growing preoccupation with these Prolonged and continued use or engagement despite any negative consequences That’s the short answer, the long answer is that there are many levels to addiction, and these may stretch all the way back to childhood as a creative, resilient way for a child to cope with difficult situations. In terms of the body’s neurobiological response to addiction, researchers classify addiction as a disease of the brain and note three distinct stages or levels: binge and intoxication, withdrawal and negative affect, and preoccupation and anticipation.