Addiction What is addiction? Addiction is the continued use of a mood altering substance or behavior despite adverse dependency consequences, or a neurological impairment leading to such behaviors. Addictions can include, but are not limited to, drug abuse, exercise abuse, sexual activity and gambling. Classic hallmarks of addiction include: impaired control over substances/behavior, preoccupation with substance/behavior, continued use despite consequences, and denial. It is characterized by the following : The person continues the addictive behavior despite the consequences The frequency or intensity of the behaviour increases over time When the behaviour is stopped, the person experiences unpleasant feelings and emotions.