From Historically, addiction has been defined as physical and/or psychological dependence on psychoactive substances (for example alcohol, tobacco, heroin, caffeine and other drugs) which cross the blood-brain barrier once ingested, temporarily altering the chemical milieu of the brain. Broadly, addiction is defined as the continued use of a mood altering addictive substance or behaviours despite adverse consequences. [1] Some defining characteristics of addiction include impaired control over the substance/behaviour, preoccupation with the substance/behaviour, continued use despite consequences, and denial. [2] ~ Addiction can also be viewed as a continued involvement with a substance or activity despite the negative consequences associated with it. Pleasure, enjoyment or relief from actual or perceived ailments would have originally been sought; however, over a period of time involvement with the substance or activity is needed to feel normal. [3] Some psychology professionals and many laypeople now mean 'addiction' to include abnormal psychological dependency on such things as gambling, video games, food, sex, pornography, computers, internet, work, exercise, adrenaline, idolizing, watching TV or certain types of non-pornographic videos, spiritual obsession, self-injury and shopping. [4][5][6][7] ~ The American Society of Addiction Medicine begins their definition of addiction by describing it as "a primary, chronic disease of brain reward, motivation, memory and related circuitry. "[8][9] ~ Drug addiction can simply be defined as a "chronic relapsing disorder characterized by persistent drug-seeking and drug-taking behaviours". [10] ~ Drug addiction can be controlled by voluntary 12 step programs, group therapy, one on one therapy, and mandatory methadone maintenance. Treatment programs can be successful in treating the addiction. Without treatment, active drug addicts often end up dead, incarcerated, or in institutions. [11]