Addiction is the term most most people use when they talk about substance use as a problem.
Britain's National Health Services defines addiction as "not having control over doing, taking, or using something, to the point where it could be harmful to you. Addiction is most commonly associated with gambling, drugs, alcohol and nicotine, but it is possible to be addicted to anything."
People become addicted for many different reasons and this may include the initial pleasurable feelings associated with taking a substance. As a person's reliance on the substance increases, they are unable to get through the day without it and require larger amounts to get the same feelings of pleasure. Here, we explore some of the issues around addiction.