The current model to explain addiction suggests that addiction begins with the basic pleasure and reward circuits in the brain, which involve the chemical dopamine.

The terms ‘addict’ and ‘addiction,’ in particular, are often used as shorthand labels to convey a number of stereotypical notions about people who take drugs. Even when not used as labels, they are terms that should be used with caution, because they are often understood by drug users and workers to imply belief in the notion of drug dependence as a ‘disease’.

This is mainly because advocates of the philosophy of Narcotics Anonymous (NA) and Alcoholics Anonymous (AA) use the term ‘addiction’ in this way. NA and AA believe addiction to be ‘a progressive and terminal disease’ which ‘can only be arrested by complete abstinence from all psychoactive substances.’ Although these beliefs have been helpful to many people in getting (and staying) off drugs and alcohol, the approach does not work for everyone and has little to offer those who do not want to consider stopping drug use.

Using the terminology of drug/alcohol dependence can be more objective because it implies recognition that dependence on a substance involves a range of physical, psychological and social components.

These reward centers are designed to activate during pleasurable acts such as eating. Whenever ingesting a substance causes these reward circuits to activate, addiction and dependence is possible. However, addictive behaviors that are considered damaging or destructive have characteristics that distinguish them from normal behavior (see common characteristics of destructive addictions. Examples of common destructive addictions are alcohol intoxication, alcoholism, cocaine abuse, drug dependence and abuse, methamphetamine abuse, narcotic abuse, and substance abuse.

People with addictions often cannot quit on their own. Addiction is an illness that requires treatment. Treatment may include counseling, behavioral therapies, self-help groups or medical treatment. People often assume that those with addictions should be able to quit by simply making up their minds to do so. Addiction is thought to be possible for a wide range of chemical substances. Dependence, most often related to physical symptoms, can occur for a subset of the chemicals that cause addiction. For instance, rarely an individual is prescribed a medication by a doctor for a legitimate reason (such as pain after an injury) and this can lead to physical withdrawal symptoms if this medication is stopped. Even more rarely, this post-medical treatment drug dependence can lead to drug abuse. People with drug abuse problems are individuals whose brain biochemistry has been altered by alcohol or drugs.