When someone mentions addictions what usually comes to mind is physical dependence on a chemical substance like marijuana or alcohol. The truth is that physical dependence is only part of the picture.
Addiction has more to do with a behavior than a substance.
So the truth is that it is not what you use, but how you use it that indicates addiction. This being the case, it is possible to say that someone is addicted to almost anything - food, gambling, sex, work, religion, Internet, or exercise. There are two factors that can help determine whether a person is addicted to some activity or substance. The first is how they use it and the second is how it affects them. If a person engages in an activity in a compulsive way, that is, a way in which the person feels they do not have the option or ability to control their actions, it could indicate a problem.