How many addictions are there?

Addiction is about mood-altering: changing the way we feel -- ultimately by changing our brain chemistry. We can do this by drugs, alcohol, physical activities, and just about any other behavior that is capable of taking us away from ourselves for a period of time. There are as many different potential addictions as there are things that will mood alter.

More useful is this catch-all description of addictive behavior: something that you keep on doing even though it is causing life-changing consequences. This applies equally well to all addictive issues.